Can I use a PC license to play the Mac version?

If I buy SimCity for PC, released this week, will I need to buy it again when the Mac version comes out or does the PC license entitle me to the Mac version?

I have checked the SimCity Mac FAQ but this doesn't contain any helpful information.

I've found one forum post from a Maxis developer saying that you can (about half way down) but is there a more definitive answer before I end up stuck with the PC version?