It'd be nice to get easier animation controls, some performance optimizations (calculate single surface for welded primitives?) and some additional texture options. Other than that, I can't really think of anything I want out of Forge that isn't in the game. I guess making some of the really awesome stuff people accomplish easier would be nice to elevate the baseline of Forge maps.
Also, going to bookmark that Ragnarok map I hadn't seen the Waypoint browers with custom screenshots before. It's so nice. Crossing fingers we get that at launch; it's nice to have a custom content solution that's finally better than what Reach came up with.
custom textures
and they allow those with Skyrim/Fallout mods (unlike Sony)