It's an interesting question. They are definitely continuing on through next year, as Worlds is in Los Angeles. Of course, they have to make the US team, which will be harder with M&B now being eligible for Worlds.
http://www.inoueandbaldwin.com/2008worlds.html
Inoue and Baldwin, who became engaged on the ice after their free skate at the U.S. championships, now plan another round of shows in Japan before returning to their home in Los Angeles to begin training for the 2009 Grand Prix season. They have other plans too: Baldwin revealed they are planning a summer wedding and hope to become parents in the not-so-distant future. They also do not rule out competing for a spot at the 2010 Olympics in Vancouver.
The link is to their account of their experience at Worlds. Do check out the pictures at the end of the story. Some of them are very funny, and they are of the whole US world team, not just John and Rena.
I can see why they are encouraged about their Nationals and Worlds, despite finishing tenth, especially considering their ages and the very short training time they had for both competitions.
John landed his triple toe in the long in both competitions, and they landed all their jumps at Worlds. They dusted off their triple twist, never very good, and at least got credit for the rotation in the short, although it was badly performed. Rena landed her throw triple loop both at Nationals and Worlds, and landed one of 3 triple axel throws (at Nationals) fully rotated but with a very shaky landing. They did fall afoul of some changes in COP for death spirals, footwork and pair spins, but I doubt that they see fixing those as a major difficulty, given the Grand Prix season to get input on them.
It sounds like they are taking things very much one event at a time, so Olympics is a stretch, but you know, I'd love to see them there. I always root for the oldest people in whatever competition.