Technically it works now to a lesser degree, the thing usually goes by the name the orb of deception. Given the implied laziness that seems to be inbound with 3.2 it stands to reason they may simply use the same logic (and part of the code possibly) to make the change.
I mean how else would you plan to do it? You let any player of any race pick any other race and it gets messy on a few levels.
You do realize that neither an Undead or a Gnome can be Druids, right? A Blood Elf can not be a Warrior, or a Shaman. Those are four big ones off the top of my head. I'm sure there are other class limitations as well.
The Orb of Deception has nothing at all to do with this discussion because, hey... it doesn't actually change your race. It just makes you look like another race.