Nokia's Mysterious house

Nokia introduced its new nomenclature system 6 months ago with C, X, E and N series. The also gave a roadmap (image below) for 2010-2011.

All these handsets have been launched except X7, E6 and N9. But things have not gone exactly according to this roadmap. E7, C7 and X7 are topped by N8 but I cant see any difference save the camera. Infact with 4 inch CBD and physical keyboard E7 looks better than N8. It would actually had been an N8 killer with the autofocus. Did nokia introduce the fixed focus in these phones just to maintain the crown position of n8? There seems to be no other reason... I hope N9 has autofocus even if it is 5 MP.
Another thing is the S series. It is on top of n9 like the chimney of the house. S series with a different color looks mysterious. S could have meant Android but Nokia CEO has denied it. So. . . Windows phone 7? It is more likely it denotes Symbian^4.