Ok some guy got his iPhone activated with his o2 uk. How about this:
Restore your iPhone to 1.1.4
Grab a baseband dump of the latest firmware and unluck it like the say on iphone-dev.org
Then flash that unlocked baseband and do your upgrade to 2.0.
iTunes wont update your baseband because it matches with the new one and you should be activated and UNLOCKED (but not JBd).
What do you think about that?