Apparently, not everyone who received one of those fancy voucher codes from BlizzCon 2008 was accepted into the first wave of invites for StarCraft 2. A Blizzard representative explained on the Battle.net forums that "due to the sheer number of BlizzCon attendees, we could not get everyone in with the first wave." That being said, you might want to reconsider dropping $300 on one of those vouchers.
The poster confirmed that these neglected BlizzCon attendees "will be included in a future wave, possibly within the next two weeks." We're hoping the wave isn't restricted to just this group of globetrotters, and that us plebes can get our hands on the highly sought-after strategy title as well.