I have both, the Rebel and a Sony HDR handycam. We used to take the Rebel, but now use the camcorder. We have gotten more into videos than stills (the Rebel takes GREAT stills!) My rebel doesn't take video, couple years old. The handycam takes pretty nice stills- it has an easy to use still button. I love the HD quality of the camcorder and we are also getting the HD helmet cam to go with it. The camcorder will give you better zoom ability and other video features I would think.? Does the new rebel have HD video??
You'll probably get a more stable pic from the video camera...small easy to hold. Tough to view screen on handycam when shooting though. No eyepiece on ours, just the screen.
The rebel has more parts/lenses etc to deal with when out in the wet/cold...I like the simpleness of the camcorder when out shooting and ease of holding etc.
We use our footage for DVD's, posting on vimeo etc...and want to get into HD. I would suggest the camcorder if that's what you want to do. Our buddy takes all his footage with his reg. camera and it turns out pretty good. But harder to hold, less features, no HD ability. With things going HD, I'd think you'd want that ability if purchasing new.