Not yet in the US (nobody really knows when), but outside the US, some T-Mobile subsidiaries do, from what I've read.
If you use your iPhone in the US, you can unlock your iPhone using one of several hacking tools, and then T-Mobile will be happy to sign you up, either for phone-only service, or phone and data. It's a little cheaper than ATT, and depending on where you use the iPhone, you might get better (or worse) reception than with ATT.
No, T-mobile does not have the iPhone. AT&T has it though.
T-Mobile does not have the Iphone only At&t does
There will not be an iPhone 4S for T-Mobile but you can get any iphone unlocked at unlockatt.com
The iphone4 is not coming out on t-mobile.
Yes, the iPhone 5 has been available on T-Mobile since February 2013.
No it is not. It is for AT&T unless you "jailbreak" and "unlock" an iphone. Instructions to do this can be found on the internet.
No.
Yes
Yes it does.
NEVER.
Yes, you need an unlocked & Jailbroken iPhone. Which isn't cheap.
The iphone is available for t-mobile custumers even in the us, i called t-mobile to find out and they said yes. The only way to really know if is you ask the source. The iphone does have a sim card. You cant trust everyone and an easier way is to call them, you just have to wait awhile for a representative or go to your local t-mobile store.