I always wondered why T-Mobile killed off the unlimited Wi-Fi calling feature a bit back. I know some people are still grandfathered into it for the $10/month or so but they stopped offering it awhile ago. TmoNews managed to get a screencap of an upcoming feature stating that starting May 11th T-Mobile will be offering unlimited Wi-Fi calling again and it looks like it will be free AND not use your plan minutes which is impressive.
UMA Wi-Fi calling is one of the strong suits of T-Mobile and their BlackBerry offering so its great to see the bringing this back! Hopefully this pans out and all T-Mobile customers with UMA phones get the free unlimited calling. Thanks Tashanna for the tip!