Not sure of the importance of this news. If it were big they would have pushed to announce it at Summit. Sounds as if they are going to build on the Office 365 platform - in addition to the work that Sage had already been doing on Azure.
Your guess is as good as mine.
http://www.sage.com/company/news-and-events/2015/09/14/sage-announces-expansion-of-global-technology-agreement-with-microsoft