21mp, yes. I used to use a 20d @ 8.2mp. In school i have been printing up to 20x30 prints @ 360dpi. with 8.2mp @ 360dpi, it would become a just under an 8x10 and if i wanted to make it bigger, i would ned to expand on that and add pixels that should be there. So when I make larger prints, its not as sharp as it should be. Now I wont have that problem. As video, I almost always have a tripod on me. I have a very light carbon fiber tripod that I use. As for auto focus, there are two different types, one is quick and can not be used during video. The other is slow, but can be used during video. I used the quick one, and manually focus when I need to. As for live view, its cool but when I do shoot work, I connect my camera to my laptop and view the pictures that way. Now with live view, I can see the live view on my laptop. That fucking badass for studio shoots!!
I will be posting a whole little review this weekend about noise, video, etc. Give me some time, I got finals this week.
As for what glass, currently I have a 28-135mm usm is. Just after christmas, I am buying a 24-70 L 2.8. I also have a 70-300 usm is.