Now that Andreessen invested a huge amount in them, I'm counting the days until it's being acquired by Facebook. Seems to be his modus operandi. An easy 20x ROI with this strategy.
Facebook is a tech rollup, and in my opinion, if they keep absorbing the most promising startups (and allow them to run independently), they could be a trillion dollar company with FB the social network making up less than 10% of that market value.