by the way, pre ordering is not the ONLY way to get the beta key. All you have to have is an active battle.net log in and you opt in for the beta and have a chance of getting a key. I have 5 keys from that. SO, if you are stating that 41000 people who play on sc2 beta have pre ordered the game already you are wrong.
I am way long on this stock but I do not like it when people post incorrect information.
This is not intentional misinformation. You have to suspend belief to believe the people who have beta keys (whether they preordered or not) are not going to buy the game when it comes out. People beta test because they are excited about the game and want to learn it before other people. All the people playing beta will buy the game. And everyone who bought the first starcraft and liked it will buy this one.