Sim, existem novas fontes no Windows 8.
Há uma postagem no blog detalhando as novas fontes - Suporte a fontes e scripts no Windows 8 Consumer Preview .
Observe que algumas letras da interface do usuário do Segoe foram reprojetadas, conforme mostrado ( fonte no MSDN ):
No Windows 7: 
NoWindows8:
A tabela a seguir lista scripts recém-suportados no Windows 8 e fontes associadas:
New scripts Script origin Fonts Comments on language usage
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Glagolitic Europe Segoe UI Symbol Historic
Gothic Europe Segoe UI Symbol Historic
Old Hangul East Asia Malgun Gothic Historic (Korean texts)
Old Italic Europe Segoe UI Symbol Historic
Lisu China Segoe UI Lisu
Myanmar Southeast Asia Myanmar Text Myanmar, Shan, Karen
N'Ko Africa Ebrima N'Ko and other Manding languages
Orkhon China Segoe UI Symbol Historic
Do blog:
The UI font changes are as follows:
- Ebrima font: updated to add support for Ethiopic and NʼKo scripts
- Gadugi font: new font for Canadian Aboriginal Syllabics and Cherokee scripts
- Microsoft JhengHei UI: new font for Traditional Chinese script
- Microsoft YaHei UI: new font for Simplified Chinese script
- Nirmala UI: new font for South Asian scripts (Bangla, Devanagari, Gujarati, Malayalam, Odia, Telugu)
- Segoe UI (certain weights): updated to add support for Arabic, Armenian, Georgian (Mkhedruli), Georgian Khutsuri, Hebrew scripts
Algumas fontes foram atualizadas:
Comic Sans gets a legitimate italic and bold italic - New Typefaces for Windows 8
Outras fontes: