[timezone]

Unlike Apple who I believe forces one to have a phone plan before using Wifi is not an issue with these phones. Now I am not 100% sure but you do have some issues. First, I have an old 6.5 phone that at the moment I still use for GPS. With a Wifi connection I can use anything on the phone. I believe it is still true with these new phones.

Now the issue. If you get a phone without a contract you are paying full price. A guess but I bet the return time window is short and if out of the box you may just get a store credit. What if it gets scratched? With a phone contract you get 14 to 30 days to test. Even with plans from two cell companies for 14 days it will not cost as much as the potential loss from purchasing a phone at full price. If you are 90% sure you will switch and just want to test then I think having two plans for a short while is really the better deal. I made a similar move by testing the HTC HD7 with Tmobile. I had the additional issue of deciding to leave Sprint. I tested with a Tmobile number and within a week I made the switch and ported my Sprint number to Tmobile. The Windows Phone 7 on an HD7 is fantastic. I bet you are going to love the new OS. Good luck with your decision.