Nokia commented later today: (via various blogs, e.g. here)
“While it is our policy not to disclose details of our product roadmap, we’d like to explicitly communicate that we remain firmly committed to Symbian as our smartphone platform of choice. Any speculation on what our 2012 roadmap, including operating systems and product branding, are completely premature.
As we have stated earlier, Nokia has multiple platforms to serve different purposes and address different markets. Symbian is more successful than ever in bringing smartphones to the masses. Maemo is our software of choice for devices based on technology that you’d typically find inside a desktop computer. It delivers a different user experience and enables us to widen the market we can address.”
In other words, the change is being dismissed as 'premature'. Maybe someone in the Maemo team is being somewhat dressed down at this very moment for getting carried away?