For local co-op you don't need two copies of the game. Just sayin...

And I somehow doubt that the mug will be of high enough quality that you really want to drink beer out of it. But who knows? Eventualy it will be great, I surely still hope so. In that case a 2nd mug wouldn't be the worst thing to have.
Running the game on two separate PCs still better than local co-op even when multi-monitor support for sure is helping the local coop.
If the mug is not good enough to drink from it then I never gonna buy a CE from them again. Kitsch mugs for a vitrine donエt fit to my interior design, and with the amount of beer my wife is bringing home recently some beer mugs seem really useful to me. ;-)