『iOS 7 の隠しフォント， ヒラギノ角ゴ W1/W2 を CSS で指定する』という記事を読んで、「あれ、これってPrivate APIにあたるんじゃない？」と思いフォント名一覧を出力してみたので、そのついでにその一覧をここに掲載しておきます。
（追記2013/10/17その１）
iOS7で追加されたフォント、iOS6で追加されたフォントがわかるよう色分けしました。
（追記2013/10/17その２）
iOS7の新機能のサンプルコード集、『iOS7 Sampler』 で新フォントを確認できるようにしました。
サンプルコードを提供されてもビルドできない！というデザイナーやディレクターの方は、ぜひお近くの開発者に実機インストールしてもらってみてください。
（追記ここまで）
何に使うのか？
self.hogeLabel.font = [UIFont fontWithName:@"Helvetica Bold Oblique" size:10.0];
みたいな感じでシステムフォント以外の UIFont を使う場合にこのフォント名が必要になります。
どうやって出力したのか？
UIFont の familyNames メソッドと、fontNamesForFamilyName: メソッドを使います。
NSMutableString *str = @"".mutableCopy; for (NSString *familyName in [UIFont familyNames]) { [str appendFormat:@"<b>%@</b>\n\n", familyName]; for (NSString *fontName in [UIFont fontNamesForFamilyName:familyName]) { [str appendFormat:@"- %@\n", fontName]; } [str appendFormat:@"\n"]; } NSLog(@"%@", str);
（ここに貼り付ける用にHTML+はてな記法で出力してます）
一覧
合計でファミリー数が71、フォント数が236でした。
iOS7で追加されたフォントに (iOS7) 、 iOS6で追加されたフォントに (iOS6) というマークを付けてあります（iOS5, iOS6, iOS7のリストを出力して比較するコードを書きました）。
Thonburi
- Thonburi-Bold
- Thonburi
- Thonburi-Light (iOS7)
Snell Roundhand
- SnellRoundhand-Black
- SnellRoundhand-Bold
- SnellRoundhand
Academy Engraved LET
- AcademyEngravedLetPlain
Marker Felt
- MarkerFelt-Thin
- MarkerFelt-Wide
Avenir (iOS6)
- Avenir-Heavy (iOS6)
- Avenir-Oblique (iOS6)
- Avenir-Black (iOS6)
- Avenir-Book (iOS6)
- Avenir-BlackOblique (iOS6)
- Avenir-HeavyOblique (iOS6)
- Avenir-Light (iOS6)
- Avenir-MediumOblique (iOS6)
- Avenir-Medium (iOS6)
- Avenir-LightOblique (iOS6)
- Avenir-Roman (iOS6)
- Avenir-BookOblique (iOS6)
Geeza Pro
- GeezaPro-Bold
- GeezaPro
- GeezaPro-Light (iOS7)
Arial Rounded MT Bold
- ArialRoundedMTBold
Trebuchet MS
- Trebuchet-BoldItalic
- TrebuchetMS
- TrebuchetMS-Bold
- TrebuchetMS-Italic
Arial
- ArialMT
- Arial-BoldItalicMT
- Arial-ItalicMT
- Arial-BoldMT
Marion
- Marion-Regular
- Marion-Italic
- Marion-Bold
Menlo (iOS7)
- Menlo-BoldItalic (iOS7)
- Menlo-Regular (iOS7)
- Menlo-Bold (iOS7)
- Menlo-Italic (iOS7)
Malayalam Sangam MN
- MalayalamSangamMN
- MalayalamSangamMN-Bold
Kannada Sangam MN
- KannadaSangamMN
- KannadaSangamMN-Bold
Gurmukhi MN
- GurmukhiMN-Bold
- GurmukhiMN
Bodoni 72 Oldstyle
- BodoniSvtyTwoOSITCTT-BookIt
- BodoniSvtyTwoOSITCTT-Bold
- BodoniSvtyTwoOSITCTT-Book
Bradley Hand
- BradleyHandITCTT-Bold
Cochin
- Cochin-Bold
- Cochin-BoldItalic
- Cochin-Italic
- Cochin
Sinhala Sangam MN
- SinhalaSangamMN
- SinhalaSangamMN-Bold
Hiragino Kaku Gothic ProN
- HiraKakuProN-W6
- HiraKakuProN-W3
Iowan Old Style (iOS7)
- IowanOldStyle-Bold (iOS7)
- IowanOldStyle-BoldItalic (iOS7)
- IowanOldStyle-Italic (iOS7)
- IowanOldStyle-Roman (iOS7)
Damascus (iOS7)
- DamascusBold (iOS7)
- Damascus (iOS7)
- DamascusMedium (iOS7)
- DamascusSemiBold (iOS7)
Al Nile (iOS7)
- AlNile-Bold (iOS7)
- AlNile (iOS7)
Farah (iOS7)
- Farah (iOS7)
Papyrus
- Papyrus-Condensed
- Papyrus
Verdana
- Verdana-BoldItalic
- Verdana-Italic
- Verdana
- Verdana-Bold
Zapf Dingbats
- ZapfDingbatsITC
DIN Condensed (iOS7)
- DINCondensed-Bold (iOS7)
Avenir Next Condensed (iOS6)
- AvenirNextCondensed-Regular (iOS6)
- AvenirNextCondensed-MediumItalic (iOS6)
- AvenirNextCondensed-UltraLightItalic (iOS6)
- AvenirNextCondensed-UltraLight (iOS6)
- AvenirNextCondensed-BoldItalic (iOS6)
- AvenirNextCondensed-Italic (iOS6)
- AvenirNextCondensed-Medium (iOS6)
- AvenirNextCondensed-HeavyItalic (iOS6)
- AvenirNextCondensed-Heavy (iOS6)
- AvenirNextCondensed-DemiBoldItalic (iOS6)
- AvenirNextCondensed-DemiBold (iOS6)
- AvenirNextCondensed-Bold (iOS6)
Courier
- Courier
- Courier-Oblique
- Courier-BoldOblique
- Courier-Bold
Hoefler Text
- HoeflerText-Regular
- HoeflerText-BlackItalic
- HoeflerText-Italic
- HoeflerText-Black
Euphemia UCAS
- EuphemiaUCAS
- EuphemiaUCAS-Bold
- EuphemiaUCAS-Italic
Helvetica
- Helvetica-Oblique
- Helvetica-Light
- Helvetica-Bold
- Helvetica
- Helvetica-BoldOblique
- Helvetica-LightOblique
Hiragino Mincho ProN
- HiraMinProN-W6
- HiraMinProN-W3
Bodoni Ornaments
- BodoniOrnamentsITCTT
Superclarendon (iOS7)
- Superclarendon-Regular (iOS7)
- Superclarendon-BoldItalic (iOS7)
- Superclarendon-Light (iOS7)
- Superclarendon-BlackItalic (iOS7)
- Superclarendon-Italic (iOS7)
- Superclarendon-LightItalic (iOS7)
- Superclarendon-Bold (iOS7)
- Superclarendon-Black (iOS7)
Mishafi (iOS7)
- DiwanMishafi (iOS7)
Optima
- Optima-Regular
- Optima-Italic
- Optima-Bold
- Optima-BoldItalic
- Optima-ExtraBlack
Gujarati Sangam MN
- GujaratiSangamMN-Bold
- GujaratiSangamMN
Devanagari Sangam MN
- DevanagariSangamMN
- DevanagariSangamMN-Bold
Apple Color Emoji
- AppleColorEmoji
Savoye LET (iOS7)
- SavoyeLetPlain (iOS7)
Kailasa
- Kailasa
- Kailasa-Bold
Times New Roman
- TimesNewRomanPS-BoldItalicMT
- TimesNewRomanPSMT
- TimesNewRomanPS-BoldMT
- TimesNewRomanPS-ItalicMT
Telugu Sangam MN
- TeluguSangamMN
- TeluguSangamMN-Bold
Heiti SC
- STHeitiSC-Medium
- STHeitiSC-Light
Apple SD Gothic Neo
- AppleSDGothicNeo-Thin (iOS7)
- AppleSDGothicNeo-SemiBold (iOS7)
- AppleSDGothicNeo-Medium
- AppleSDGothicNeo-Regular (iOS7)
- AppleSDGothicNeo-Bold
- AppleSDGothicNeo-Light (iOS7)
Futura
- Futura-Medium
- Futura-CondensedMedium
- Futura-MediumItalic
- Futura-CondensedExtraBold
Bodoni 72
- BodoniSvtyTwoITCTT-Book
- BodoniSvtyTwoITCTT-Bold
- BodoniSvtyTwoITCTT-BookIta
Baskerville
- Baskerville-Bold
- Baskerville-SemiBoldItalic
- Baskerville-BoldItalic
- Baskerville
- Baskerville-SemiBold
- Baskerville-Italic
Symbol (iOS6)
- Symbol (iOS6)
Heiti TC
- STHeitiTC-Medium
- STHeitiTC-Light
Copperplate
- Copperplate
- Copperplate-Light
- Copperplate-Bold
Party LET
- PartyLetPlain
American Typewriter
- AmericanTypewriter-Light
- AmericanTypewriter-CondensedLight
- AmericanTypewriter-CondensedBold
- AmericanTypewriter
- AmericanTypewriter-Condensed
- AmericanTypewriter-Bold
Chalkboard SE
- ChalkboardSE-Light
- ChalkboardSE-Regular
- ChalkboardSE-Bold
Avenir Next (iOS6)
- AvenirNext-MediumItalic (iOS6)
- AvenirNext-Bold (iOS6)
- AvenirNext-UltraLight (iOS6)
- AvenirNext-DemiBold (iOS6)
- AvenirNext-HeavyItalic (iOS6)
- AvenirNext-Heavy (iOS6)
- AvenirNext-Medium (iOS6)
- AvenirNext-Italic (iOS6)
- AvenirNext-UltraLightItalic (iOS6)
- AvenirNext-BoldItalic (iOS6)
- AvenirNext-Regular (iOS6)
- AvenirNext-DemiBoldItalic (iOS6)
Bangla Sangam MN
- BanglaSangamMN
- BanglaSangamMN-Bold
Noteworthy
- Noteworthy-Bold
- Noteworthy-Light
Zapfino
- Zapfino
Tamil Sangam MN
- TamilSangamMN
- TamilSangamMN-Bold
Chalkduster
- Chalkduster
Arial Hebrew
- ArialHebrew-Bold
- ArialHebrew-Light (iOS7)
- ArialHebrew
Georgia
- Georgia-BoldItalic
- Georgia-Bold
- Georgia-Italic
- Georgia
Helvetica Neue
- HelveticaNeue-BoldItalic
- HelveticaNeue-Light
- HelveticaNeue-Italic
- HelveticaNeue-UltraLightItalic
- HelveticaNeue-CondensedBold
- HelveticaNeue-MediumItalic (iOS7)
- HelveticaNeue-Thin (iOS7)
- HelveticaNeue-Medium
- HelveticaNeue-Thin_Italic (iOS7)
- HelveticaNeue-LightItalic
- HelveticaNeue-UltraLight
- HelveticaNeue-Bold
- HelveticaNeue
- HelveticaNeue-CondensedBlack
Gill Sans
- GillSans
- GillSans-Italic
- GillSans-BoldItalic
- GillSans-Light
- GillSans-LightItalic
- GillSans-Bold
Palatino
- Palatino-Roman
- Palatino-Italic
- Palatino-Bold
- Palatino-BoldItalic
Courier New
- CourierNewPSMT
- CourierNewPS-BoldMT
- CourierNewPS-ItalicMT
- CourierNewPS-BoldItalicMT
Oriya Sangam MN
- OriyaSangamMN
- OriyaSangamMN-Bold
Didot
- Didot-Bold
- Didot-Italic
- Didot
DIN Alternate (iOS7)
- DINAlternate-Bold (iOS7)
Bodoni 72 Smallcaps
- BodoniSvtyTwoSCITCTT-Book
過去のiOSバージョンとの比較
同じコードをiOS5と、iOS6でも実行してみました。
Version Families Fonts iOS5.1 58 163 iOS6.1 61 199 iOS7.0 71 236
だいぶ数が増えたようです。
参考までに、下記記事は iOS5 の頃に同様の方法で一覧を出力したものです。