I hate it how 1.6.1 laucher updates it for you grrrr when EMC takes time to just wish they let us do it yourself.
You can choose which version you want to play, from alpha to 1.7 snapshot, you can configure it yourself.
EMC is now running on 1.6.4 Though you can connect just fine with 1.6.2, 1.6.3 and 1.6.4 clients (far as i can tell)