The new 5d Mark II has 21.1 megapixel Full-frame CMOS Sensor which will give us opportunity to print bigger images. It has Extremely high ISO settings and a lot more lovely features like a video capture at 1920x1080 pixels in Full HD :D
For more datailed informations check full review on www.dpreview.com
Here are images /from www.dpreview.com/ of this lovely tool:
Front view:

Back side with a battery grip:

Specs view:

The 5D Mark II should be for sale by late November...
I will get one of this for sure and off course I let you know what I think :)