Firmware 2.0.1 is available.
I just started a restore on my 3G and iTunes asked me to update my phone to 2.0.1!
More info to come!
Update: Also available for iPod touch owners.
Update 2: So far, after upgrading, my iPhone 3G seems to be overall quicker. Apps load faster and keyboard lag is just about non-existant.-ajl917
If your phone is pwned and you hit upgrade in iTunes you will get error 6 and you will have to re-pwn your phone with the custom 2.0.0 software.
The current versions of Pwnage and WinPwn will not work with 2.0.1 right now!! Stay posted for updates to these programs!!-ajl917