I think we need to agree to a definition of a micro brew -
for me, it has to be localized. any beer i can get coast to coast is a domestic beer, not a micro beer.
Microbrewery - Wikipedia, the free encyclopedia
seems some consensus is that a micro brewery cannot produce more than 15k barrels per year.
this is kinda interesting below re craft beers (which i think a lot of folks are talking about in this thread)
"regional craft breweries, which make between 15,000 US beer barrels (1,800,000 L) and 6,000,000 US beer barrels (700,000,000 L), of which at least 50% is all malt or contains adjuncts that are used only to enhance flavor"