Google yet to officially disclose about Android M but the name leaked out yesterday accidently when Google revealed about parts of Google 2015 I/O event. By looking on the topics of Google 2015 I/O sessions we can conclude few things about what new features Google will adding on Android M.
First feature of Android M will be "Voice Access", Google will tell developers at I/O how to develop apps with hand free capabilities. Second prominent feature of Android M will be "Nearby". Google mentioned "Nearby" feature session as "Proximity-based communication". It seems using this feature Android users can communicate with other Android users in a certain location.
The next Google Android OS design will remain focused on Material Design that’s why Google held couple of sessions at I/O 2015 regarding material design. One of the session is named as Bringing Material Design to life on Android”.
Google might also add VR on Android M because one of the session is "explore virtual reality and how it may change our lives". Google is also planning to reveal the new wearables at the I/O 2015 and they mentioned that these wearables will "blow your socks off."
Google 2015 I/O event will kick-off from May 28th and will end on May 29th in San Francisco. So far Google didn't published official app of 2015 I/O event where as last year Google released official app which allows Android Lovers to see some sessions video streaming.