Wouldn't it be cool if in G/S/C if you could pick any/all of your Poke'mon to walk behind you by pressing START on them? Then you could choose which Poke'mon you wanted to go out first instead of the Poke'mon on the top of your list coming out first.
It'd also be cool if the Poke'mon had icons like they do in R/S/E. Then you could actually see what the Poke'mon looks like.