If you installed Expression Blend2 August Preview you probably noticed the splash screen prompts you for a product key...even giving you a link to get this key. Unfortunately there was a little confusion with the folks that built the splash screen as Blend 2 August Preview comes pre-keyed which is good through Oct 31. Unfortunately the link the splash screen directs you to doesn't have a key as there are no keys for this build.

Microsoft, Expression Blend2, Product Key, License Key, Software

Source:? Ozzie