Android Lollipop is currently being distributed to older models of smartphones and is already available out of the box for most if not all new models of smartphones. As this is happening, rumors are already abound that a new version of the mobile OS, initially called Android M, is in the works.
The latest version of the mobile OS is rumored to be in development, with a mention of it being included during the upcoming Google I/O 2015. According to a report in Android PIT, Google may likely unveil or announce the upcoming OS during this meeting which occurs at the end of May, following with the actual release in October or November this year.
In terms of its name, Android M is merely a placeholder for what is expected to be a "sweeter" name, going by how Google has named previous versions of the OS. With no official announcement yet, speculations range from Android Marshmallow, Android Milkshake, Android Milky Way, Android Mars, Android Milky Bar or Android M&Ms. Most reports cited their preference for Android Marshmallow.
Design-wise, the Android PIT report cites that the upcoming version may not be a big step up from the design of Lollipop. It said to "expect evolutionary and refinement rather than a gee-whiz new look."
In terms of features, Android M is rumored to bring forth improvements in notifications, such as attempting to unify notifications across platforms and going beyond the smartphone to the PC or the tablet. It is also said that the Smart Home feature of Android will be further improved on, allowing for wireless control over connected devices in a home or in an office.
Android M is also expected to promote the use of Android Wear, by making sure that there is seamless integration with these devices. Further security enhancements are also expected to be introduced in the new version. The report also mentions that Google may start introducing Android Auto, which is the new software being developed for cars, for easy access to navigation, maps and other useful apps.