The Skype for Business team has launched the much awaited calling features in preview mode. US customers are now able to call landlines directly from Skype for Business, as well as enjoy landline conferencing in Skype for Business webmeetings!
You can sign up for the preview at: www.skypepreview.com
If you are located in Canada, you can still test this by adding a USA based user for testing.
Also in preview is Skype for Business on Android and iOS.