I know that recently that At&t bought T-Mobile, does this mean that I'll still have to unlock my iPhone 4 to make it work with the T-Mobile network? Or will using any non-contract iPhone 4 work with T-Mobile?
AT&T is in the process of getting approval to buy T-Mobile. Not bought as yet. As a result both companies still operate as they have. Separate. So yes you will have to unlock it for it to work on T-Mobile.
well att has not bought t mobile yet, so yes you will have to unlock it for tmobile ... if att does end up buy tmobile it will rob ably be a year or so before their phones are compatible anyways
I know that recently that At&t bought T-Mobile, does this mean that I'll still have to unlock my iPhone 4 to make it work with the T-Mobile network? Or will using any non-contract iPhone 4 work with T-Mobile?
No, At&t hasn't bought t-mobile, so you need to unlock your iphone4 to remove att network lock and then use t-mobile in the iphone4 . You can unlock it using remote unlocking service without any risk at Theunlockarena.com/unlock-your-phone/rs13wp2/