iPhone Dev Team today released redsn0w 0.9.9b8 which will natively support yesterday released iOS 5.0.1 Beta. Download Link is available below with basic feature list.
Dev Team announced the release in their blog like below
redsn0w version 0.9.9b8 will natively recognize the 5.0.1 beta that Apple let developers start testing this week (so you don’t have to play the “point at 5.0 IPSW” trick). Because the IPSW isn’t public, you’ll still need to provide it once to redsn0w (at which point it will cache all the important pieces so you don’t need to select it again).
For those 3GS and i4 users who preserve their baseband, the Mac version can also produce the NO_BB_* custom IPSWs for 5.0.1. (But please note that ultrasn0w doesn’t get updated for betas like this.)
This is still a tethered jailbreak for all except old-bootrom 3GS users.
You could use our Old Guide to use this redsn0w.