I think it's pathetic to whinge about having to drop just $5 on an app store version when a lot of users originally got it through a discount bundle such as Macheist. Especially as it will update to any future version (3.0+) for free and the existing app isn't going to expire, as stated in the blog post.

Look at any other company, Apple isn't going to give you a free code to say, Aperture 3 just because you own the pre-MAS serialized version.