The unconference part needs organization. More to come soon.

@Qgil: Which aspects?
Apart from general WikiDev stuff itself (venue, accommodation, equipment, cost, registration, catering, insurance) I see:
Have rooms, have a large whiteboard in a central location, post-it stickers (for session name plus session owner), thick pens, potentially small round stickers to express +1s. Define length of sessions before (45min?) and draw a grid on whiteboard. Explain in the first morning session how things work. Make people put up their proposals at random timeslots. Make people vote. Make sure popular proposals don't collide too much. Have someone responsible for creating a table on a wikipage of that whiteboard. Make session owners responsible for documenting their sessions on an Etherpad (cf. T120693) and link to the Etherpad on the wikipage.

• ...and potentially having assigned session roles: http://adainitiative.org/2013/10/02/running-your-unconference-discussions-effectively-adacamp-session-role-cards/ (which would have to be prepared, be available in each room, and the session owners need to be told in the first morning session).

"Survey results say a good moderator and gatekeeper is the key to a good session", to quote Valerie.

• "Potential additional role to assign in each session: Reporter": Turn results of each session into a 90sec lightning talk; present at end of the day in a dedicated all-audience session

In T120939#1872476, @Aklapper wrote:

@Qgil: Which aspects?

Essentially the ones you have been mentioning, and maybe more. @RobLa-WMF is putting together https://www.mediawiki.org/wiki/Good_meetings -- which is directly related (but not restricted to the unconference tracks, it applies to pre-scheduled sessions just as much).

We found a specialist and a modest budget. More news hopefully soon.