If you already have a MCTS then you need to take exams 457 and 458 to get the MCSA, from there you take 464 and 465 to get MCSE. If you have MCITP you take 457, 458 and 459 so 1 less exam, but in order to get to MCITP from MCTS you need to take the ITP exam so it works out at 4 exams either way. Unless your starting off at certs when you need to take 5.

2008 will be with us atleast until 2019 and personally we dont have a big reason to jump to 2012 just yet (although I am pushing it for AlwaysOn). In terms of just upgrading to 2012 certs or getting 2008 certs, I think its a matter of personal opinion, personally I want to get 2008 certified as that is the major core platform we work on and then maybe sometime next year when we have more of a push to go 2012 then upgrade then.