Just like I did previously, I have managed to update my iPhone with the new OS 3.0 software and remain unlocked. Currently you can unlock all iPhones except the new iPhone 3GS (but this should be available in the next few weeks, click here to keep up to date on this on the Dev-Team Blog). Because I am using an old first gen iPhone model it was a really straight forward to update.
I hit up iClarified as before and followed their instructions to download the jailbreak/unlock tool - http://www.iclarified.com/entry/index.php?enid=4302 - install was simple and quick to do. I think the whole process took me just under 30mins from start to finish but you will need to allow for some time when downloading the files required for this.
Just make sure you sync your iPhone before you run the update so you can do a restore once you're finished and restore all your contacts and data. My iPhone 2G is now running on Meteor without any problems. Enjoy!