well, i think you need to look at things this way:<p>a) A big trend emerges, it's the cutting edge. All new. aka Web 2.0 three years ago. It brings about new philosophies, cost structures, ways to communicate,etc. An entire culture thrives around it, tons of money is poured in, and we find out what works via trial+error.
b) This trend eventually normalizes and becomes "standard". Everything we learned via this trial and error, becomes part of all products. Social networking is becoming less and less a "site" as it is becoming an integrated feature of existing properties. It's also influencing the way startups are run and built. Think about it, the trends + technology in the past 3 years, have made it possible for things like YC to exist (OS software, low cost requirements, ease of distribution, distributed teams,etc.)<p>So in short, not it's not over, it's just becoming assimilated into everything.