Although we can't seem to find anything official on the matter, there has been several reports coming in that T-Mobile has been rolling out a 2MB update to enable Wi-Fi calling. Right now, it seems only BlackBerry Q10's are getting the update. There was a small batch of folks who got it shortly after the MR update but it seemed to stop after that. If you've been waiting for the services to be available it might be worth a shot at checking for updates. Sound off in the comments if you're seeing it and we'll update the post if we hear anything official on the matter.