This is just for point releases, you still get access to betas of major new versions, not to mention the ability to sign apps and publish in the app store, which is what that $99 is really about...

It continues to confuse me why Apple has two separate $99 developer programs, especially since to be an iOS developer you need a Mac anyway, and considering the amount of code-sharing that can happen between Mac and iOS apps I'd think they'd want to encourage developers to move across platforms?