Jericho makes a good point, they could do with a new star.
But I still think it's too soon, Ryback is unproven, it could be a huge pay off to give him the title but it could all lose momentum real soon and the WWE has a real habit these days of dropping the ball on a good thing.
I really expected Punk to lose the title soon only to win it back before RR just because I couldn't see the E letting him wear the title for over a year. But he pretty much has to face The Rock at the Rumble and it's too late for him to lose the belt just to win it back, this close to the rumble it would be too rushed. So I think the E are actually letting him hold the belt for over a year (roughly a year and 2 months) which is great for Punk as lack of maineventing aside to hold the belt for over a year is impressive and it makes his loss to the Rock even bigger. Should he lose the belt only to win it back just to drop it to the Rock a month or two later would make Punk losing the belt far less potent.
So I think Punk has to walk out champion, which is why they've really booked themselves into a corner on this one.