It has been announced some time ago already but we have been waiting for the official release.

This is it, you can now download the Skype for Business Cloud Connector to connect your existing PSTN with Office 365 like this

image

Download link http://aka.ms/getcce

Once you have downloaded and installed it, follow the steps detailed here for the configuration

https://technet.microsoft.com/en-us/library/mt605227.aspx