Update (sorry for double-posting but I thought It worth a bump):

Looks like http://wiki.meego.com/N950/Fixing_MALF_state works quite well, at least for my N950. (Sorry, couldn't get myself to brick N9, so It's up to you to confirm ) So If you're affected from this problem, just do as that wiki page says, then remove Air UI as soon as possible. If you're lucky enough, you won't have to reflash. (which brings this question to my mind: if this was possible from the day one, WHY the hell did they implement a MALF screen to force users to reflash. >_>)

Note: It displays a way scary notice about your warranty is now void, so if you want to do this on your warranty-covered N9, you may want to think again.

Note #2: Most likely unrelated but to let you know, I activated R&D mode and no-lifeguard-reset flag before doing this, and my Ubuntu Oneiric didn't recognize/misrecognize (as a one big partition named sdd) partitions on my first tries, don't lose hope if it doesn't work for you on your first try.