I'd like to know the answer to this as well. I have an Imperial Server (my main server) then I rolled my Republic side characters on another server. The problem I have is I want to move a high level character from the Republic server, to the Imperial, so this answer is important to me.
Also, I would like to hear the answer to this one:
As someone with lots of alts I want to be able to gear them with the stuff my level 50's have access to, so spending credits and/or commendations on something that is useless after a couple levels makes me sad.