So how do can we solve this problem of drinking from a firehose?

I think a system like Google Reader system might have some traction here, wherein friends can recommend items to each other. With enough friends, you could make a metafeed out of those items. Make it a new service; you get paid for drinking from the firehose, and you pay to get human-filtered feeds. Throw some 'liked/hated this firehose drinker' and a pile of people at it, and you get interest spaces.