I think Daniel Bryan will surpass him as far as fans go. I am a huge Punk fan but D-Bry has the crowd appeal going.
I agree with this, though I'm don't want to since to me, Punk > Bryan. Bryan's popularity has been this high for nearly 18 months. Punk has gotten likewise mega pops before (his hometown in MITB 2011 comes to mind, and then a few of them during his heel run last year, just listen to the crowd at Summerslam that year) but he hasn't been this consistently over in just about every town he goes to for this long before. If Bryan keeps it up, then yes, he will surpass Punk in the long haul (though I'll always like Punk better.)
That said, Punk is definitely already a shoe-in for the HOF. Barring doing something horrific similar to Benoit or offending Vince McMahon in such a deep way that he'd never forgive you (such a thing almost isn't possible), then you can be sure that the following people of the current roster will all be inducted into the HOF one day: John Cena, Undertaker, HHH, Brock Lesnar, CM Punk, Daniel Bryan, JBL, Michael Cole, Randy Orton, Chris Jericho, Big Show, Christian, Kane, Rey Mysterio, Mark Henry, etc. Del Rio and Sheamus already have plenty of accolades to their name and will no doubt add more by the time they hang the boots up, so they'll almost certainly go in, though neither will be a headliner. Same goes with Miz. Tensai/Albert/A-Train hasn't accomplished much but he's a veteran so I could see him being one of the early inductees of a HOF ceremony one year, too.
