Ubuntu has a much larger development community, also, comparing them side by side, personally I think maemo has made a lot more progress, at least visually. Not to mention, wtf has ubuntu got to do with an embedded platform of hardware _and_ software. Nokias' contributions to FOSS over the past 6-8 years has been pretty substantial, ranging from kernel all the way to the desktop, any company that does that gets a nod from me, it's pretty rare in this corporate lawyer driven world.