Microsoft has been a little sloppy with SP2. I wonder if they put too much of a testing burden on Beta and CTP testing and getting feedback.

I got this from an MVP, who heard it at the MVP Summit two weeks ago. I've never seen hotfixes mentioned that they include previous ones, but from a coding perspective, it makes sense. If you had 4 hot fixes you were working on, would you have 4 branches of SP1 code? Or 5 including the SP2 branch? Would you then try to merge them together?

No, you'd build on the previous hot fix code.

I think this is a huge failing on Microsoft's part in not making this very clear to people in all their products and linking to the previous service pack and hot fixes that are included.