With the above in mind, I think 4e does make it easier to play a tank-centric campaign, since nit-noid details of keeping the tank up and running is sufficiently abstracted. A PC mechanic could take a lot of pride in keeping 'the beast' repaired and working, which gives the player a nice raison d'être to be part of the party.

I mean, imagine being a STR 8 Mechanic 8 PC and being told repeatedly, - no, don't bother rolling, you don't have the exact part need... why show up for the next session if that happening multiple times in a game?