Gosh. In no particular order;

• H&FJ
• Klim
• Process Type Foundry
• Fonthead
• Jeremy Tankard
• Mark Simonson Studio
• Porchez Typofonderie
• House Industries
• Stone Type Foundry
• Emigre
• Feliciano Type Foundry
• Typotheque
• Letterror
• FontShop
• Alphabet Fonts
• Type Supply
• Village
• Typopheque
• Bold Monday

and probably more by the time you read this are supporting Erik van Blokland and Tal Leming’s intelligent, pragmatic and just downright clever .webfont proposal. You should too.
Source: Mr Hoefler's Twitter feed (@h_fj) and Tiff Wardle