I often use dual heads on my MBP, and I was wondering if there was a way to have separate applications running in full screen on each display? So for example full screen mail on one display and then my other application running in full screen on the other?
No fun, but the answer is no. Best you can do is choose which screen your app goes full screen on, which is a minor improvement on previously. It's tricky to accomplish due to the new screens workflow, an extended desktop onto a 2nd monitor is still just one 'screen', and you want it to display 2 different screens simultaeniously - a not unreasonable request, but one which is sadly unsupported at present.