I'm kinda bummed about the plastic body news. In my mind, the 7D is now the real replacement for the XXD line and this 60D is really a new level of camera stealing the name from the XXD line. I'll reserve final judgement until I see the product, but so far, I don't like it.
Tell us how metal vs plastic body will make any difference to your photography. And anyone else who thinks this is a change for the worse. Explain how the magnesium alloy is the core of the camera and without which you could not take a decent photo.
Have you even held a plastic body D/SLR to know what it is like? Let me clue you in - it's lighter. Pair a plastic body camera with a good plastic lens (50/1.8mkII) and you've got a winning combination that can take awesome pics in low light because there's very little strain on your muscles to keep it steady.
I actually did in another thread but I can't expect everyone to read each thread, so I'll explain in more detail...I can be clumsy and my camera gets beat and dinged all the time. I was figuring that it stood a better chance of surviving w/ a metal body. And if my camera survives, it will take a better photo than a broken one

. If you would have read down the page a little you would have also found that I said I was becoming more ok w/ it if they used a high quality plastic and if they still put an XXD shutter in it (as I do shoot a TON of frames).
Here is a good example of what I mean...back when the 1DS came out my old boss took it out to get some photos. He was walking over a bunch of boulders, slipped and put his hands down quick to catch himself. Problem was that the 1DS was still in his hand

The base of the camera hit a rock so hard the 28-70 2.8 broke right off the body, leaving the lens mount in the camera, and it ejected the battery (not sure if you have seen 1DS batteries, but they actually lock into the body). He got back to the studio, we removed the mount, put a new lens and battery in and it worked perfect. Fast forward to this year and a buddy of mine drops his Rebel XSi w/ a kit lens on it. Doesn't hit the ground hard enough to break the lens or cause any visible damage. His camera now doesn't work. Now I'm not saying that the 60D is built like the 1DS, so everyone quit writing the flame responses, but I figure that it has to fall somewhere in between as far as durability.
Do I need the durability? Not if I don't drop my camera

. But I make money w/ my camera and a lot of times I'm chasing kids or at a wedding and I'm focusing more on my subject than on my camera. I know there is a really good chance of me doing something stupid

If you misunderstood and thought that I was saying my pictures would look worse now that it was a plastic body, I'm sorry. All I was saying was that I can tend to be clumsy and I figure a more solid body is a better insurance policy for me.
Anyway, that's my reason FWIW.