The iPad 2 WiFi & 3G model from AT&T is actually unlocked and works with UK data plans, as tested by Macworld today.
The situtation is expected (after all the original iPad was also unlocked) but will come as a relief to customers looking to pick up an iPad 2 from a visit to the States, or by purchasing one and having it delivered to the UK. The iPad 2 is shipped with an AT&T MicroSIM card, but removing this and inserting a UK MicroSIM also provides a data connection.
Macworld tested the iPad 2 with a MicroSIM card from Three, and the data connection worked fine.
Potential customers should be careful to buy an AT&T iPad 2 model, and not a Verizon iPad 2. The AT&T model comes with a MicroSIM card which can be swapped for a UK MicroSIM card. Verizon, however, does not use SIM card technology and there is no way to get a data connection from a Verizon iPad 2. So be sure to get the AT&T model (or a WiFi only unit).
The AT&T card from an iPad 2 WiFi & 3G can be replaced with a UK MicroSIM card for mobile data connection.
At the top left you can see the 3 symbol, which shows that the data connection is being provided by the Three network.