Update:
BlackRa1n is out now and I have wriitten a guide on how to use it and jailbreak iPod Touch 3G/2G and iPhone 3GS/3G/2G:
Yesterday Apple released iPhone firmware update to fix a few bugs and thanks to Apple that they didn’t fixed the exploit found by the GeoHot to jailbreak all iPhones and iPod Touches.
GeoHot has Twitter that BlackRa1n still works on the new 3.1.2 firmware as he successfully jailbroke his iPhone 3GS running the latest OS 3.1.2.
This doesn’t mean that you should go ahead and update to OS 3.1.2. Read the Golden Rule:
Never update to any latest firmware if you’ve a jailbroken and/or unlocked iPhone.
GeoHot also notified that there will be delay in BlackRa1n release. We will keep you posted as there comes any update. Stay tuned.