from the conversations on the meego- dev list t's quite clear that Harmattan is NOT dead and there's a whole team, seperate from the Meego team, in private.

stskeeps in his role as N900 Meego HW adaptation, in his quest for as much speed as possible for Meego or ARM, talks openly very often with a Nokia ARM performance guy, and he always talks about asking the 'harmattanam team when he does status updates.
his issue are very much ARM/neon/hard FP related, and if the best person in Nokia to talk to the performance guy of the Harmattan guys is ... what do you think ? He was even saying on the hard FP issue, that Harmattan had faced this issue before the Meego team. Of course, they had at least 6 months head start.
My gut feeling, no intel in Nokia's next Harmattan based handheld ...
future will tell if they stick to ARM, i have no glass ball but I'm convinced the N9/whatever will be ARM based.

For sources, check the meego-dev mailing list archves, everything from stskeeps is very good and informative for N900 owners.