So the thing surprising about this is that Fitbit's stock just took a nosedive, their financials are questionable (but maybe the holidays will be good to them again) and they're acquiring a company in a market where there is a clear leader (Apple) but as whole, the market itself appears to have hit a peak or is in decline.
Even if they got a steal the whole things seems like a bizarre move. At best they integrate Pebble into their lineup, get some good brain power in SV (they are HQed in MA I believe) and build out their future products with Pebble's finely tuned developer ecosystem (their opensource SDK is amazing). At worst, they go down in flames and in the fire sale they fetch a little more for owning Pebble IP.