The local reports were that Anchor had been slowly losing money for years before the Sapporo acquisition. Supposedly Sapporo was intending to use the Anchor facility to brew Sapporo locally and then eventually found out that the site wasn't really suitable or would require too much renovation. Whether this led directly to the Stone deal, I don't know (I doubt it, given relative sizes, but it may have been a contributing factor). In general, even before the Sapporo acquisition, Anchor was slowly getting pushed out of local bars by other, smaller local breweries. Once I started seeing things like Standard Deviant's kolsch or Harmonic's pilsner taking up one of the taps in smaller restaurants that only had 2-4 taps, the writing was probably on the wall.

I suspect one of the local breweries will be happy to acquire Anchor if Sapporo's going to sell it off at fire sale prices (c.f. Cellarmaker/Rare Barrel, Drake's/Bear Republic).