Not sure if this will meet your needs but you can check out Bandicam. It claims you can start recording webcam video with the press of the "F12" key. I haven't used it so I can't say for sure it works.
I stumpled upon this thread while looking for the same thing. A simple program to record from webcam in fullscreen.
While the Windows 8 camera app does that, you cannot change the resolution and it always records in low resolution. If it were not for that it would be great.
I found a good software, Arcsoft Webcam companion, it has these features, however while using the software my screen sometimes would flicker a lot and close some other programs randomly.. maybe it was some compatibility issues, don't know.