We have been shooting with the 10D for over a year or so now...We used two for the magazine when I was publishing it....trust me when I say...the 6.3 mega pixel is two page spread full size, high end magazine quality print!
I agree with the others too...it all depends on what you are looking for when shooting. If you just need a quick point and shoot for the shows and also amatuer style shooting...then don't worry too much....the lower quality sometimes the better when it comes to amatuer style shooting.
If you are looking for the bells and whistles, the 10D has it just about what any pro is looking for in a digital slr camera.
I am looking at upgrading to the Mark II as well. Just read a review about it the other day.
Also....I totally agree on the REAL Canon USM lenses too...that is all we will buy....it is amazing how many people go out and get a great camera then go cheap on the lenses...you might as well not get the camera then.
You need to deside what is best, low cost or high end and quality.
Oh....let's not mention all of the learning I hope you have experienced already to be able to maximize the effectiveness of having such a great camera.
Let's talk lighting, filters, whitebalance, warming effected, etc.
Good luck though...it is a great camera!
Oh...last word of advise...if you are looking for the best deal on the net...make sure they say it is Canon USA - that is important...otherwise you could get the camera and it doesn't have a warranty or isn't in your language or the settings are not US standards...then your fucked. There is a HUGE gray market out there right now, don't get sucked into it or you will regret it.