If Facebook, Meebo, Bebo, Plentyoffish, iminlikewithyou, justin.tv, reddit, digg, Pandora, Last.fm, Hotornot, TechCrunch, PodShow, Boing Boing, Life Hacker, Prosper.com, 43 Things, SixApart, Gawker Media, 37 Signals, Wordpress.com, Scribd, and Zimbra all went out of business tomorrow, simultaneously, we would not see the huge rash of pink slips we saw in 2000. The stock market would not crash because of it.
It's not the same at all. Funny names != a bubble, and neither do over-valuations by private investors, and neither does a lot of entrepreneurs trying to start companies. It's called capitalism. Get used to it.