I'm getting to this thread EXTREMELY late, so I haven't read all the other posts here yet. If I repeat anyone, I apologize.
When I was watching Raw tonight, I was actually surprised that the Alberto Del Rio/Rey Mysterio match went on as long as it did. I was expecting that we would see Cena at the end of the night (since we didn't see him during the episode), and I was not shocked at all to see him make the save for Rey.
Since this was Rio's first title-defense, I don't think the WWE higher-ups wanted to end the show with him. He's not "established" enough as a champion yet, and they needed an "established" star to close the show. That "established" star just happened to be Cena.
To be honest, I thought that Nash's "explanation" would have closed the show (when HHH revealed that Nash would be at Raw at the top of the show). I figured that HHH & Nash would talk in the ring, Punk would interrupt (like he did when Nash was in the ring), then Cena would come out...but I like the way that the WWE booked Raw tonight.
Obviously we're going to see a Punk/Nash match soon, but probably not for a little while. I originally was thinking it could be a wrestlemania match, but I don't think that this "feud" can stay hot until 2012. Maybe Nash costs Punk his rematch for the world title, or something....I dunno.
Like I said earlier, I liked the way that Raw ended tonight. Cena got to do his whole "the WWE Championship is the only thing that really matters to me!!" speech, and directed it at Alberto. It was done well, and ended the show on a good note (at least IMHO). Just my two cents, anyway.