GTA IV was on the weekly discounts a couple weeks ago, so it's probably not that.
L4D2 and Lego Batman 2 were also on discount in the first week of July.
Personally, I would love to see Oblivion (since Skyrim is a long shot) and Borderlands 1. But I would also like to see some children/family oriented titles. I wouldn't mind an XBLA platformer like Battleblock Theathre.