I don't think there is any question that the turf helps the Giants. Fast TE's will be helped as well, yes, but they are not as fast as fast WR's. Considering the Giants' penchant for big plays, many of which are catches and runs, I would be a little surprised if the Giants didn't have a small handful of big gainers Sunday. Welker is more quick than fast in my eyes, and his 99 yd TD earlier this year aside, is not as big of a play guy as a great possession guy.
Same goes on defense. I would be shocked if Osi, JPP, Tuck, etc are not Freeney-esque and Mathis-esque on the Indy turf, showing incredible speed. NE does not have the same speed the Giants do on defense.
I think intangibles are on NE's side (revenge factor, everyone picking the Giants to win, etc), but I don't see how the Giants cannot score 30 in this game, and if the Giants' d-line is on, I think they make it tough for Brady to score 30. Plus, I think the crowd is likely to be 60/40 minimum for the Giants (Indy fans will be rooting for the "other" Manning and hate NE) which will be an advantage.