Well...you have the option to Re-Roll on a more populated server but I am guessing you don't want to lose your Levels.

I seriously doubt SE is gonna close down and merge servers though, so a more pertinent question would be, "Can we get a World Transfer Service after billing starts?"

If I were in charge my answer would be, "Yes, once billing commences we will offer a one-time World Transfer Service...for a Fee of $9.99".