If you want to beat the rush, 3.0 is available now.
This thread will probably be removed, but here goes nothing. I stumbled across the 3.0 software on a questionable Swedish service that has been in the news lately. The current build is 7A341. I downloaded it in a matter of three or four minutes. It is the real thing and it works as advertised. There is a noticeable speed boost. Search is rad. Everything seems to perform as demoed. I will not be eligible for the 3Gs until may, 2010. This update should tide most people over if snappiness is the main concern. Best of all I didn't have to wait all day while ten million people hit the Apple servers in a couple of days.