It is now a ghost of what it was, and it IS irrelevant. Facebook has moved in and trounced it. However, I will posit that Facebook is dead man walking and they don't know it.
Facebook is losing members. Facebook is losing relevance. Facebook will go the way of MySpace. I can hear the gasps now.
In the technology sphere, what goes up, must come down. Remember how Lotus Notes once dominated the market space. Remember DEC -- Digital Equipment. Let me take you further back. Lowell Massachusetts was the home on Wang -- a company that went from zero to the stratosphere with dedicated word processors. They went the way of the dodo bird.
Those crazy valuations of Facebook that one is hearing about should be a sign to investors. Get out now, and sell short. You won't regret it.
What will come next? I don't know. But what history teaches us, that fad cycles are getting shorter and shorter, and a plethora of new offerings are coming to the market daily. One of them will reach the tipping point, go viral, and make a new billionaire, leaving the oldies (of less than ten years) in the dust.