While I love Aqua, and it's got some nice improvements over the OS9 Platinum interface, I'd love to see focus follows mouse in it...
Also it would be nice to see X clipboard-like support in Aqua apps for people that have multiple button mice... select and middle-click are so much quicker to me than cmd-c, cmd-v... I don't suppose either of these will happen though, since it would likely require changes to Aqua and/or the API.
I can dream though...