Apple has released the iPhone firmware 3.0.1, which is a release to fix the SMS attack (the hackers can take control of your phone by sending you a SMS) and it doesn’t have any major update. iPhone Dev team had claimed that the redsn0w 0.8 can still be used to jailbreak the iPhone firmware 3.0.1. The trick is that you just need to locate the iPhone firmware 3.0 instead of the iPhone 3.0.1 for redsn0w to identify. You can still unlock your iPhone with ultrasn0w from Cydia installer.
So, if you’re still thinking whether to update your iPhone to iPhone firmware 3.0.1, after reading iPhone Dev team’s claim, you should be able to make your decision now.