A couple of reasons that point to it being a work:
1. He still stands to collect a big main event payday at his alleged last WWE appearance at the PPV in a few weeks. Punk's made some good money in 6 years and maybe he's really frugal (he's def. saved some dough on not going out and drinking). That being said, I can't see someone as smart as him doing anything to jeopardize a PPV payday
2. They edited out whatever comment he made about John Laurenitis, which means they're on some kind of a delay. 30 seconds at least but it could be 1 to 2 minutes. That's about half of the length of his rant. They could have cut it or pulled the plug a LOT sooner.
3. If this was totally not part of the show, why no security to come and escort him backstage?
Also to people talking about the Joey Styles rant, if I recall correctly that was both before or right during the PG era turn, and I'm almost positive it was before the Superbowl wardrobe malfunction that's now infamous that caused several t.v. networks that weren't using delays on live feeds to start using delays. I'm not as expert to know when WWE switched to a delay on their live shows, but its very possible they had no delay back then that they have in place now. They may not have had the time and chance to react to pull the plug with advanced screening of the show 30 seconds to a few minutes in advance of it hitting the airwaves.
4 (Update after reading WWE article) - that makes me even more suspicious. With the comments he made, why not just fire him? He's "allegedly" leaving in 3 weeks anyways. You're going to suspend the guy instead of terminating him???
Plus if you want to pull a work/shoot like that, you want it to look as authentic as possible. The whole cutting the mic and the cold finish would all be part of the work to make it look like a good shoot angle.
I'm calling work as my theories above leave it a little more than suspicious to being a real shoot. If this were the PPV, I'd buy it as a shoot, but not 3 weeks before.
Update - Another thing that struck me, is that I've read that WWE's ratings have been falling into the toilet. Good ol "shoot" on a guy that's allegedly leaving at the PPV is a great way to spark excitement in the wrestling community. "Holy crap did you hear what Punk said Last week ?!?!?!?!?!?!"
Update 2 - Look at the fishy wording from the WWE article about his "suspension" (directly quoted from the article)
"With his WWE contract expiring on July 17, one can only assume that this suspension effectively terminates CM Punk’s tenure with WWE.”
One can only assume that it effectively terminates his contract? When have you ever heard them use a phrase like that when someone is legitimately leaving or being legitimately suspended?? Sounds like code talk to me that he'll be back. Remember when Matt Hardy was released and had his legitimate feud with Edge where he made several appearances from the crowd? I can see Punk buying some tickets to next week's show or showing up as a "fan" in disguise.
Update #3 - Next week's raw show was taped right after this one and the results are already online.