I don't think it has to be the council who decides; we're facilitators. However, if no-one else volunteers, we'll have to find a way.
A call for content sounds sensible. Don't know. Practical logistics like sponsorship, work arrangements etc. probably dictate this by simply working backwards.
Fremantle & Harmattan sound like a sensible theme, but you know more than us on whether this'll be a "You got your fremantle devices last week, here's what can be done with them" or "so, fremantle devices have been out for 4 months now here's the state of the ecosystem" or "as you know, we're shipping fremantle devices next month". No experience. The wiki worked last year, but seemed a little chaotic. Certainly proposing a talk shouldn't mean trying to fit it sensibly in the schedule.