The chaps over at HardForum have stripped their new BFG PPU card down and water cooled it.  Surprisingly, the mounting holes follow the good old GF4 standard so no problem to find a suitable block. There aren't any currently-released games (except Ghost Recon: Advanced Warfighter PC) that take advantage of the PPU, but UT2007 and several other upcoming games have announced that they will support it.