had a 1.1.4 16gb iphone that i used ziphone on, used the unlock all feature in ziphone months back, i have a o2 contract but NOT iphone one and basically i ran the download installed 2.0 fine, went through the activation in itunes etc, by logging in using my email/password from itunes account and it come up 'activated iphone'. Then restored all contacts/music etc from back up file.
Working like a charm, as i say i am on a o2 contract but not iphone so so far so good .......