For the lazy:
So these purport to be the very first screenshots that someone has valiantly leaked, probably risking life, limb and lawyer ninjas to do so. I do like the LoL-ish cel-shading on the ground, in fact aside from the UI it looks pretty indeed.
Although, mainly I'm excited because it's Valve and I've had so much fun with TF 2 that I might be able to deal with the inevitably horrid community to have fun, like with LoL.
If these are fakes or from another game then please post so.
Edit: another screen added