Glad to see another Colemak user :)
For Emacs there really isn't a need to remap, since the initial "shortcuts" aren't designed to be close to each other. If anything, you're gonna be more comfortable using Emacs on Colemak than on Qwerty (at least I was).
In Vim it's a lot trickier since hjkl will be completely messed-up. Then again, I've always felt that hlkl was broken and should have instead been jkj; or ijkl, so a remap is probably a good thing. Here's a broader discussion about Colemak+Vim on the Colemak forum: http://forum.colemak.com/viewtopic.php?id=50
