Updated information: http://us.battle.net/wow/en/forum/topic/1015371759?page=6#110

Can I race change into Death Wing and wreck havoc upon Azeroth for a couple of days?

I believe that sort of wizardry would require a Flux Capacitor, the Arrow of Apollo, and maybe an eye of newt.

You wouldn't happen to be a Newt?

I'm mostly a dragon kite. Mostly...

Paid Race/Faction Change to the new class combos will be available as soon as they are available to create (with the release of 4.0.3a)

This is an update to the previous expected functioning of this service. We're in the process of ensuring everyone here has this latest updated information, just know that this is what's now accurate. :)

Paid Race Change to the new class combos will be available as soon as they are available to create (with the release of 4.0.3a)

This is an update to the previous expected functioning of this service. We're in the process of ensuring everyone here has this latest updated information, just know that this is what's now accurate. :)

Will this be the same as for when Goblins and Worgen come out?

If i buy a race change NOW will i be able to just save it and use it on DEC 7th to change to a goblin?

I've been told that if you buy a race change now you can simply wait until the new race/class combos are available to use it. I don't see why that wouldn't also apply to goblin/worgen, but I haven't seen specific confirmation.

If it's comforting, when you click the button to change race you can actually cancel out and not use it. When you click on the button you're not forced to use the race change request right then and there. In any case I guess my point is you could cancel out and seek further assistance.