WhatsApp Beta is 2.12.38 finally bring the calling feature to Windows Phone but its only for the private beta testers. I got a good opportunity to check it out. Call quality is pretty good for now but has some distant issues.
Also i got a couple of errors while trying to call a friend who has it already on android which asked me to reboot the phone.
I made 2 -3 calls and received a call and it works really fine though I was using wifi.
The next step would be to test in it using 3G connection, lets see how that works and i’ll let you all guys know about it.
For now have a look at the screenshots and get ready for it, but we don’t know when is it going to hit the public version of WhatsApp.