This is a majorly revamped version of the first concept. (Updated: now has the classic yellow text under the logo, has description of game mode in Singleplayer tab, and has new login screen concept)
P.S. Please download the ZIP to see the whole concept!
I have an idea if your willing to listen :L You could include a metro tab that shows your minecraft avatar. in spoutcraft they have a avatar viewer for minecraft in the launcher.
That's a good idea... Or, when you first open the app and this screen shows the avatar runs onto the screen and stands on the right, just like on the XBOX Dashboard.