There's a whole thread on this in this very forum. That being said it is most likely possible to do but not exactly very nice to the people who want black iPhones but have been unlucky enough to not be able to obtain one.
This question has been floating around for three weeks. No one has successfully done it yet.
No-one has successfully delayed their gratification? I believe it.
BL.
I have a slight twist on this question,
Can I purchase the black one now with my upgrade and then purchase the white one (unsubsidized) when it becomes available and use the same SIM?
The reason I ask is because I want to try both out and see which one I like more and sell the other one?
I don't see why not. You are paying the unsubsidized price for it.
Remember if you return your phone you will no longer be able to use the unlimited data package.
So lots of idiots couldn't wait for their white iPhones and bought black instead. Now they want to return a perfectly good phone so they can get white. There's tons of people waiting for iPhone 4s in black. Why couldn't you people just hold out for the white one if that's what you wanted all along?
The only idiot I see is you ^ since you insist on name calling.
That's called Freedom. If you have the option to return your phone within 30 days and choose to do so. Go for it.
So you return a perfectly good phone to have it go in the refurbished pile just so you can get a white one? Why not just wait for the white one to come out.