Earlier today we shared the excellent news with you that the first beta version of iOS 5 had already been jailbroken by MuscleNerd. This tethered jailbreak uses the same LimeRa1n exploit that has been used from iOS 4 to 4.3.3.
However, because it is a tethered jailbreak, the community was hoping that i0n1c's untether might still work with iOS 5, but unfortunately, it doesn't look like it...