It's a great camera in that case. It's designed as a portrait/wedding camera. Not good for low light in the off center focus points, not good for sports.
Portrait and landscape you should really like it.
I have one... I am far from in love with it. The focus system is weak and I shoot a lot of sports, so that's a killer. It's BEAUTIFUL for portraits and wedding work.
Probably an improved focus system. Either on par with the 7D, or with slightly fewer focus points. I'd also guess that the resolution would stay roughly the same, or possibly even smaller. Similar to what the 1Dx is going after.
I wouldn't be SURPRISED if Canon put in a popup flash specifically for triggering off camera speedlights the wireless flash system, but I also wouldn't expect them to do so.
It will probably also have a vastly improved video mode.
Last March I took my HS band to NY for the St. Patricks day parade. A young photographer contacted me about shooting my band as they came down the street. He was positioned in a tall building above 5th ave. He sent me a free 16x20 and then I ordered a 24x36. Both prints are incredibly sharp with no noise or pixelation. He was using a 5d mark ii
I would get the 5DII now. The Mark III when it premiers will be expensive. Will that be worth the cost difference for what you like to shoot. For what you stated the 5DII is perfect for your needs. If we keep waiting for the next model we never get what we want or need, we're always waiting.