Rumors say it will be called Lollipop, but I'm holding out for a name alphabet reset to Abba-Zaba.
Bloomberg has quite the feature on Sundar Pichai, the Google Senior Vice President currently in charge of Android. There's plenty of insight in the story -- his rise through various Google product divisions, how Pichai brokered a new peaceful relationship with Samsung, among other stories.
The most important bit of news in the feature, however, is the confirmation that Pichai will preview the next version of Android tomorrow during the Google I/O conference.
It's been roughly eight months since the last major Android OS release. KitKat (version 4.4) brought some major performance improvements to Android (particularly when running on mid- to low-range devices), but version 5.0 (or possibly 4.5) has been desired for quite some time now. Speculation points to this version being codenamed "Lollipop," assuming Google stays with the alphabetical naming scheme.
As for features, most of the leaks out in the world haven't pinpointed any major UI changes. Instead, the next Android flavor will continue to focus on under the hood, including possible support for 64-bit processors.
We'll be following Google I/O tomorrow, which promises plenty of news for Android proper, Android Wear, and possibly an Android TV announcement.