5. Open buildings
While we know current hardware has limitations which means it would be exceedingly hard to program a game of GTA 4's size with fully interactive buildings, but we still wanted it. On the next generation of consoles we expect power to be a non-issue, so when we walk up to a shop front, we want to be able to go in it. Houses may have locked doors, but we want to be able to break in. It'd be a huge undertaking, but we're talking about the next generation of the GTA franchise. The sky is surely the limit.