I see absolutely no point to upgrade to a 5D3. Especially for a $1,000+ price increase. 61-point AF system? Who cares? Who shoots with multiple points anyway? Center-point focus and recompose. That's how any serious photographer shoots anyway. Do people want their cameras to compose their shots for them too?
Leave it up to your camera to pick your focus points and you will end up lots of throw away shots.
It's just another fear-tactic designed by the marketing dept. at Canon (or any other company for that matter) into making you feel your current gear is obsolete. Even the 5D Classic is WAY more than enough (WAY WAY WAY more) for the vast majority of users. I had a 5D Classic since 2005 and JUST recently sold it for a 5D2. Although the 5D2 is great, I kind of regret the switch. I wasn't expecting a bump in image quality, I just wanted it for the video capability. The 100% increase in file size and all the software updates I had to do to support it just was a hassle.
I am glad that Canon is keeping it at 22MP. Last thing we need is a MP war with Nikon.