I didn't realize there was an official definition. Interestingly, at the time Sam Adams and other brews that were a step up from the mass market lagers in the US, as I recall a distinction started being draw between craft beers (Sam Adams, Harpoon, Anchor Steam, etc.) and microbrews--where microbrews were the very small local brews with limited distribution.

As I remember things, this first microbrew movement (as well as something of a homebrewing fad) sort of declined but it's more recently really roared back in force. On trend I've noticed recently is the big "craft" brewers like Sam Adams and Sierra Nevada have really expanded their lineups and come out with all sorts of limited time as well as higher-end products like barleywines.