People will not develop for MeeGo - they will develop for Qt. MeeGo is just the best vehicle for platforms on high-end devices. It's not MeeGo for MeeGo's sake. Via Qt, developers can target hundreds of millions of users, MeeGo ones will just be the coolest ones

One major difference is that MeeGo is not a smartphone OS. It is a mobile OS, for everything from mobile phones through cars to netbooks, giving a potential for a vastly larger ecosystem. All competing platforms OTOH are islands, with their own very specific technologies and walled gardens, with minimum spread to non-phone form factors. On top of that, MeeGo IS continuing the computer-in-your-hand paradigm (hopefully better executed than some aspects of earlier Maemos ). You wrote what current OSes are known for, but that doesn't mean a new guy can't best them at their own game, i.e. offer better multitasking than webOS, grow a bigger ecosystem of their own, etc.

This is probably the biggest advantage, though - MeeGo is the only OS that is (when fully rolled out) not controlled by a single company and can be applied to ANY mobile device, no royalties or strings attached like in the case of Google. OEMs were mighty angry when the Nexus came out because that hurt their strategies badly - nobody complained publicly though, as you don't want to get the top dog angry.

This is more a vendor question - they will sell whatever popular phone a vendor they have a good deal with offers. No OS has an advantage in that sense.

The strategy is there, it's still way too early to tell if it will play out. Considering it's the most open OS on offer today, I sure hope it does

No, but probably not it in the sense you ask. MeeGo is an OS foremost and not the end product most people will actually use, it's like asking will Windows have facebook or twitter ? It's almost certain some vendor implementations will include all that, but it's not a MeeGo question per se.