There are no other iterations of Maemo, MeeGo or Harmattan coming out that continue the OS20XX series. That's pure speculation sprinkled with hope to think otherwise. That "MeGo" (sic) article about being sold in the US is a fake. Wrong size screen, wrong spelling on the OS... I do not believe it at all.
[...] edit: just read the thread a little bit. yes, there a far, far more N9s than N900s. edit2: but I will completely tear apart the N950 as soon as I'll get the successor.