IME, which is more then most, the Canon Rebel line is pretty awesome. As far as it not being a "professional line", I am a professional, my studio uses rebels. We used to use Nikon D1X's, but find that for print quality Rebels are better. As far as Rebels not being able to print large photo's, I might agree with that to a bit. The largest I have printed was a 4 foot by 8 foot print, but it was fine. I might not use it for a billboard. That print was made from a Jpeg shot on the original Rebel a.k.a 300D.
As for the Rebels not holding up, I can only speak of my experience. I have taken a couple hundred thousand images on a rebel, rebel XT, and rebel XTI. Doing the type of work I do I take a lot of images, sometimes over 10,000 a week. I have not had a Rebel shutter die on me yet. JME
Personally I prefer Canon's, I did make the switch from Nikon as I was disappointed with the print quality and color output from the Nikon files. When I made the switch I was also not to fond of there sensor design or the amplifiers used. They may have fixed that now, I have not checked into it.
IMO the main advantage to Nikon's is the wireless link to there flash line. With the Canon cameras you need to buy external gear which is expensive.
Personally as a professional photographer with 12 years experience, the camera I take places is a Sony point and shoot. It does have the option for lens add ons. It also has the option for a water proof case. You could get the camera I have, a telephoto lens, a wide angle lens, macro is included, an external flash, and an underwater case for scuba for about a grand. Compare that with a "professional DSLR", a professional telephoto lens, a professional macro, a professional wide angle, a professional mid range, and external flash, I'm well over 5G's already.
Just saying, the little point and shoot cameras can be pretty incredible if you take the time to look at them. The sony's come with a full manual mode, which shows the exposure of the image if it were shot as it would be on the screen. I wish my 5D did that.
The other advantage with consumer camera's is they are made for the average person, you won't have to take a class or 3 to figure out how to use it, just spend a day or two with the manual.
JMO