With Roy Thomas Baker producing, most people expect the new album to sound great. He was, after all, the man behind the 70's Queen albums (which IMO includes several sonic masterpieces) and many other classic and/or prog albums since then.
Your point about this coming on the heels of the Three Album Tour is good. Many are expecting that this little chance for Yes to revisit what they did and what they were like in their classic period (even if only two or three of them were in the band at the time) will inspire new music with a similar "attitude", for lack of a better word.
And finally, Jon Davison is a songwriter. He brings a new influence to the table, which hopefully will stimulate new ideas. Howe and Downes are both good writers, but I think it's possible that when they work together, they get into something of an "Asia mindset" and tend to play it safe. Asia sometimes makes some good, interesting music, but very little of it is really prog. Fly From Here was not a bad album, but I think a lot of people were disappointed because it wasn't very prog. Not that prog = good, but because prog is what they were expecting from Yes, and instead they got something somewhere between Asia, Buggles, and DramaYes. Anyway, Steve officially left Asia last year to focus on Yes and his solo/trio work, so hopefully he and/or Geoff, in collaboration with New Jon, produce some more adventurous results.