How many video game commercials on TV do you see of games that are coming out in 2012? No one in their right mind would spend cash on a promotion like that and not have people able to buy their product.
This stunt will not generate many preorders without a firm release date. Heck they could've chosen Titan to sponsor it and got the same response.
Edit for Bashiok:
Text 1/4 down page - "Check back tomorrow for PC Games Day, sponsored by Diablo III".