The question will be more difficult to answer with MeeGo than it was with Maemo. - Maemo was always tied to a (Nokia) device; so when people said "It's not open because driver XY is closed source", they referred to a hardware+software system defined by one vendor.

MeeGo isn't tied to one single device. I guess we may see devices sold with MeeGo plus some proprietary drivers plus proprietary user interface components plus proprietary software... But does that say anything about MeeGo as an operating system if none of these proprietary components are needed to build+run MeeGo on some other reference hardware? I don't think so.

How would you answer a question like "Is Ubuntu 'truly' open?" if your Ubuntu system uses proprietary Flash, a proprietary driver for your graphic card and some non-free business software?