Logic has something called TouchTracks. You can assign any recorded sequence to any key (basically map it how you like) and control it any way you want (Transpose it, gate it, loop it, play it backwards, toggle play etc).
I was told that Cubase has something very similar, but I can't tell you what it is called. I just know that CUbase also lets you trigger sequences from the keyboard.
Try e-mailing info@steinberg.net
I can't say anything about Cakewalk at this point. Last time I've used that was over ten years ago.
My personal opinion is simple If you do music and you want things work smooth get a Mac. RIght now a used G4 costs as much as any good PC so really, all those guys complainign about the high $$$ are full of it. BUt that's just my opinion. I'm shallow that way.
-ED-