Not from what I am/was told by Apple. I pre-ordered the Verizon one this year (I am on AT&T) but I was told you have to have your account information (that being Verizon for me) to activate the phone first.
Once it is activated though, I can put my AT&T sim into it and it will work just fine.
I'm just screwed in the activation part.
Did you not have to have a T-Mobile account to active the phone first?! That would give me some hope lol