I turned my paper in on time, although it truly sucked. No amount of extra time would have improved it though -- I just don't do fact-based research papers very well. I like philosophy, literature, stuff where I can spin theories and prove my point.
Now that the paper is turned in, I have that feeling -- the after the deadline feeling. Depleted, aimless. I can't really seem to focus on anything, just want to drift in the sea of "done". Read some trash. Watch bad TV. Sit on the front porch and have a beer in the sunshine.
I guess its nature's way of forcing a re-charge. You just don't have the energy or the impulse to do anything for a while.