a) and that will be the excuse for Maemo 6 b) even the people who are working on it don't claim Mer is ready I'd love to be proven wrong but I don't think I will be. I think the N900 will end up with a more stable OS but it will be Maemo 5. It will end up with a more expansive suite of possible applications but their development will taper off as well.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...