The whole FirefoxOS thing has come far too early as the concept of HTML5 as an app won't be viable for years.

Ubuntu on phones amounts to nothing so far. You can't even make a call or send a text through their OS. Considering how much trouble it has been for Jolla (who know their ***** in making a mobile OS and already had most of the core already written) - I think it's just crazy that Ubuntu are even trying to compete in this area.

webOS is neat, but it is owned by LG who don't appear to have any interest in using it to make a phone. It is a dead platform.

BB10 is of course out now, but it doesn't really interest me as it doesn't provide the same Linux-type experience that Maemo/Meego does. It appears to be targeting Android market.

Tizen is the unknown, although I suspect they will go down the same route as Blackberry and lock down all the goodies that we were used to in Maemo/Meego.

At this moment and time, Jolla is still the closest thing to a N900/N9 successor. That is why I have put my money on the table and have pre-ordered.