A preview of the on-premises SSRS with support for Power BI is now in preview. We'll technically, it's called "Power BI Report Server" preview. But under the covers, as far as we know, it is an enhanced version of SSRS. For the SQL Server 2016 release, Microsoft completely rebuilt the SSRS engine, with full support for HTML5, and now Power BI Desktop reports.
About a year ago, we reported that both the SSRS and Power BI teams indicated future Power BI support as part of SSRS. And earlier in the year, we did an initial review of the Azure based VM that included the enhanced SSRS engine. That review found that SSRS did indeed do a nice job with Power BI Desktop reports.
The preview download is available here: Microsoft Power BI Report Server - May 2017 Preview.