Valve have posted an bunch of the outtakes from Meet The Medic over on the TF2 blog. These are genuine outtakes, and are animated storybaord mock ups and rough animated sequences, rather than the "comedy" outtakes that the animated films now so often bookend their credits with. Valve explain some of the process behind the decisions made, and how the story told in the final movie came to be: "Instead of the medigun we'd explain the origin of the ubercharge, giving us a chance to explore the Heavy and Medic's relationship a bit, not to mention a few gross-out surgery gags. Better yet, this new opening segued into our big finish far better than our old story ever had: The significance of the big ubercharge moment had some dramatic heft to it now. Even the doves were now explained, instead of just being a neat visual effect."
I've posted Meet The Medic below, just in case you needed cheering up.