Along with that, the dev team also announced the Ultrasn0w unlock for baseband between 04.26.08 thru 05.13.04, however, the redsn0w tool to jailbreak iPhone has not yet been updated.
This means that there is no way to jailbreak the iPhone as of now, and of course because of that you cannot unlock your iPhone too. However, the good news is that the iPhone dev team posted an update that jailbreaking tool for the iPhone was being updated and will be released shortly.
Remember that the redsn0w jailbreak did work on the iOS4 GM, so it should not be long before it will also work for the official iOS4 release.
So if you have not yet updated to iOS4, you better hold on till a jailbreak update is available, because if you do and rely on a carrier unlock, you will not be able to use your device.
Have fun, we will keep you updated when the iOS4 jailbreak is out for users to download.
Image Credit: LonePlaceBo