I don't think it's going to come anywhere close to the FTW shows. However, it seems like Bob has gotten his sh*t together over the last year. Hopefully, that will hold up. I don't know much about Mayer other than (as you said) he's supposedly a really good blues guitarist. I predict he holds his own, but I'm not really expecting anything magical to come out of this. I think anyone expecting Chicago Part 2 is going to be disappointed. I just expect it to be a fun time with some good music. The excitement is back in Deadheadland. That goes a long way in making a good time out of this.
Chicago was over-the-top fantastic. From here on out, everything else is just a bonus.
Confession: I've seen John Mayer.
But but but... He just doesn't fit this mold. The guy isn't an improvisational player, hell, he just started listening to the dead in the past couple of years. I just don't know how he's going to fill any sort of lead guitar role.
Anyway, I hope to snag a ticket for about $10 bucks come show time.