We have already reported that Redsn0w 0.9.8b1 can jailbreak iOS 5 Beta 3 by pointing Redsn0w 0.9.8b1 to iOS 5 Beta 1 IPSW file. But in case if you want to preserve baseband to unlock your iPhone 4 & iPhone 3GS then Redsn0w 0.9.8b1 is the not the tool for you.
Here is Sn0wbreezwe 2.8b4 from iH8sn0w updated to support iOS 5 Beta 3 jailbreak on iPhone 4 (GSM, CDMA), iPhone 3GS (Untethered), iPod Touch 4G, 3G & iPad. Sn0wbreze 2.8b4 lets you to create custom firmware with preserve baseband option for iOS 5 Beta 3 which you can restore with the help of iTunes 10.5 Beta 3.
Please keep in mind except iPhone 3GS, iOS 5 Beta 3 jailbreak on other devices is tethered jailbreak meaning you will need to connect PC or Mac and tethered boot using Redsn0w or ibooty utility every time reboot your device. Also iOS 5 beta 3 is only for users registered with Apple developer program. You need to have UUID registered with Apple in order to activate iOS 5 Beta 3 iOS device as Sn0wbreeze 2.8b4 will not bypass activation.
Also there are few reports that there is sandboxing issue on iOS 5 Beta 3 jailbreak and stock iOS apps are crashing. You may wait till Musclenerd from iPhone Dev team fix this issue.
And those who can’t wait for jailbreak may proceed for iOS 5 Beta 3 jailbreak with Sn0wbreeze 2.8b4, here is our complete step by step guide (assume iOS 5 Beta 3 in place iOS 5 Beta 1).