Take a year or so off, do solo projects, come back, record a new album (and the idea about the band laying down the music first isn't a bad one actually), tour it a little - not run themselves into the ground but good, solid, two-hour shows at decent-sized 2-4000 seat venues - and then, wrap up with a two-three day festival EXTRAVAGANZA, featuring any current and ex-Yes member who wants to come along. Fill the 'festival' event (such as it is) with nothing but songs by the various lineups of Yes, along with solo shows by all the ex-members (or their bands - Asia, Conspiracy) to fill out the time!
But I've mentioned that last idea before.
Still, just because Yes is aging doesn't mean they have to wrap it up JUST yet. I see 2007 as their last year, actually, but I could be wrong. I will say that it's pretty much pointless for them to continue on as Yes without Jon - in fact, at this point, I think any lineup 'subtraction' would prove to be fatal.