See this thread:
Since CS5 is already out, I don't see how they can include it in the suite after-the-fact, other than offer a nice discount with proof-of-purchase.
The launch plans are determined by a different group within Adobe and have not been finalized. Since CS5 has already been released, there are laws that limit Adobe's ability to make changes to existing product lines like that. As soon as I have an official, sanctioned release plan, I or someone else on the team will share it here.