it may be too late to launch the next "MYSPACE", but I don't believe success lies in trying to duplicate MySpace/TagWorld/Tagged, etc... but if you target a vertical market and base the network around "social commerce"... you may have a chance to generate substantial revenue without the need for an exit strategy revolving around being acquired. We own a stake in a social commerce network launching in 3 weeks targeting a market worth 11 Billion Dollars... and they've already signed up sponsors and users, so I know for a fact that a new social network can be successful.
but if you are trying to clone myspace, then add something unique, next-gen or have an angle, like
http://CYWORLD.com based in Korea. (
US version in BETA now) - virtual environment, marketplace, gear, etc.
or check out
http://www.asmallworld.net, very exclusive vip club type of social network.
either way... good luck.