Correct me if I m wrong, but I think it is natural that Nokia's future "mobile computers" will be based on the portable x86 architecture rather than OMAP.

The fact that nothing has been announced about the next Nokia mobile computer, in terms of specifications, might mean that they're still designing it. If that's the case I would expect the n900 to live and sell for more than one year from now..which is quite good for this kind of phones. I remember how bullocked I felt when SE released the P900 a year after I got my SE P800 =)