So rumors are abound about the next gen TBD being retina. Even if price will not be an issue (and it will be $$$), can a 2012 15" rMBP drive that monitor? Is TB 2 required for 4K? Also, with the current TBD, can a 2010 MacBook Air with mini-display port output compatible with it? I'm considering the TBD because of its awesome resale capability if the new TBD is worth upgrading to, but I won't dump my rMBP to get 4K. Thanks for your help?