http://www.shop.avanquest.com/uk/prod.php?pid=1963
Well, it's not confirmed, but if we assume that vasechka is right in this post, that's what seems to be the case.
But then again, if I look at shop.avantquest.com (the adress on the UK boxed version) and scroll down a bit, It says:
Xmas Special Offer! FREE upgrade protection
* All puchases of Parallels Desktop for Mac made between the 29th November 2006 to the 23rd December 2006 (inclusive) will be eligible for FREE upgrade protection for one year.
This means that if there are any upgrades or new releases of Parallels Desktop within the next year, you will get these free of charge!
Is this again some kind of "only from avantquest store" offer?