The real problem is that GW2 locks you in (for WvW) once you've made your server choice.
I hope they do something smart like allow 100% free transfers for full servers. Like once CD goes "full", they maybe link it with some other low pop server and say "For the next 36 hours, you can transfer for free from CD to this new server." If they announced a program like that, I'd say "okay then!" and continue with CD.
As it stands, you'll have to pay real-life cash to transfer. If it fills up and your guild can't get in, well, you're fucked. (In Rift, our first server selection really did get a 4 hour queue on the first day, so those of us who got in just decided to abandon it and start over on a new server. That won't work in GW2.)