Many people play multiple games at once and will focus on a new game for a bit when it comes out. Also, anyone with a battle.net account could get in the diablo 3 beta.
My guild took a couple weeks off of TOR to play Diablo 3 for example and are now back in TOR.
To be perfectly honest, the fact that they even thought that forcing us to all take crash in 1.2 or that the current changes to defense Guardians are good ideas shows how little they know about the class.
Good point with Malgus, it still weakens the Imperial faction though because it is now split into two warring factions. You are also right that I forgot to point out the Dread Masters part, so thank you for that.
The Empire lost Correllia to the Republic, the new dailies point this out. You lost Angral, the vast majority of the Dark Council, Imperial Intelligence, Gran Moff Kilran, your top General, and Malgus has left your faction.
My server's fleet had around 200 people on this morning and around 300 on last night. If people were really going to quit they would just leave instead of complaining on the forums.