I can't help but be ambivalent about the N9.

Yes, I desperately want Meego to become a success, due to the same reasons stated by the OP (more freedom of choice and use in mobile phones).

Yet I can't shake the feeling of a disappointing buy in the N9. Yes it's sleek, and yes it seems to have a nice UI. But it still shows all the signs of a dumbed-down phone. Non-removable battery, no microSD, no proper video-out (not even to mention HDMI)... The N9 is a step backwards in functionality. Apparently Harmattan isn't full-blooded Meego either, but a hybrid of different APIs. Does that limit us doing whatever we want to the OS? Could we completely replace the UI?

Right now there is still too much uncertainty to decide much of anything, but for the time being I can't see a reason to ditch my trusty N900.