The AC manufacturers didn't intend to make distilled water for drinking, so condensate may contain heavy metals or other nastiness.  And if the homeowner hasn't kept it clean, the drain pipe can get moldy.  But yes, with proper filtration the water could be safe for human consumption.

Slightly different topic, the amount of water industrial scale AC units generate (think big box stores, supermarkets, high rises) could probably fill many Olympic swimming pools each day.  As water becomes a more precious commodity, I think we'll see this water captured and put to use.

By the way, while the condensate water is technically distilled water, AC units are not built to make it safe for human consumption.  So don't drink it or cook with it.  More information is available here:  http://www.allianceforwaterefficiency.org/Condensate_Water_Introduction.aspx 

Officially the driest January in San Francisco in 165 years.

Florida is going through a drought, too.