Sorry about that, my fellow geek (yes, I am a geek as well). How was I to know? :)
Anyway, I was just on QuickPwn dot com, and they say that the jailbreak for 4.0 won't be out at least until after next Monday, but who knows how accurate that guess is. So far, the only utility to jailbreak 4.0 would be called limera1n, and it is said that it's the fastest way to do so. If you want, I can keep you posted, as I am subscribing to the article via RSS as we speak.