There are a lot of interesting structural dynamics in the 2016 election. Here's how we see the players. We'll categorize them by the three local factions: Republicans, Barthists, and Prop A folks.
Kristin Gaspar (Republican): Already announced Supervisor run. Opponents are Escondido Mayor Sam Abed and incumbent Dave Roberts (or a Democratic replacement if Roberts doesn't recover from the hostile work environment and improper use of taxpayer funds scandals). Gaspar is thus likely out of Encinitas politics unless she fails to make the top two in the June Supervisor primary and then announces she'll seek re-election.
Catherine Blakespear (Barthist): Likely to run for Mayor from her safe council seat (as Tony Kranz did in 2014). May not face a serious challenger because most other candidates would find it easier to win a council seat.
Tony Kranz (Barthist): Will run for re-election unless he moves out of state. Likely to win due to large number of open seats (4 if Blakespear wins Mayor seat) and likely weak field.
Mark Muir (Republican): Likely to run for re-election, won't challenge Blakespear for Mayor because it would a lot riskier than running for council. Likely to win re-election.
Lisa Shaffer (Barthist): Has said she wouldn't run again, but don't count on it.
Paul Gaspar (Republican): Seems politically ambitious and could probably win a council seat given his name recognition and fundraising ability.
Sheila Cameron (Prop A): Won't run again.
Julie Graboi (Prop A): Seems inclined not to run, but would be among the stronger Prop A candidates due to name recognition and practice on the campaign trail. Remember, Tony Kranz got elected on his second try.
Al Lerchbacker (Republican): Hasn't been seen much since failed 2014 campaign, so it's unclear whether he's still interested. However, with party backing and an earlier start and easier field this time, could probably win a seat.
So at this point we'll pencil in Blakespear for Mayor, Kranz and Muir to keep their council seats, and two other seats up for grabs.
We can think of several other Barthists who might run: the "Engage Encinitas" women and a traffic commissioner or two. We're not aware of any other Prop A folks getting ready to run. What have you heard?
UPDATE: Welcome former Sierra Madre Smart Growther Councilman Joe Mosca to the race!
UPDATE 2: Apparently the rules are such that if Blakespear wins Mayor and thus vacates her council seat, the seat does not go to the fourth-place vote getter, but is appointed by the council. The vacancy wouldn't occur until the new mayor is seated, so presumably the new council is the one to make the appointment. If Mosca wins, the Barthists would have a 3-1 majority and make an appointment to give themselves a 4-1 supermajority (which could resurrect the Barth-Shaffer-Kranz sales tax increase). If Lerch or another Republican wins, we'd have a 2-2 stalemate which could lead to the appointment of an independent, non-partisan compromise candidate.