You can purchase vBulletin right now and enjoy version 2.x
you get 1 year of free updates etc, so in this year, vb3 will be release (i am 99% sure about that) and then you get it for free.
Well that's great that we get free upgrades for a year, Theo(a fellow admin at FFL) bought FFL's a month or two ago. But I wouldn't really want it for a while unless all the hacks for 2.2.6 work for it.
Basically none of the current hacks will work with vBulletin 3, most of the coding is being rewritten, redering the hacks useless (some of the authors said they would update the hacks, although some may not).