Multi-user profile support has been available on tablets for some time but is yet to appear on Android phones. However, a recent post on the Android issue tracker may suggest that it’ll appear in the Android L release.
A post was created complaining about the lack of support for multiple users on phones and was quickly responded to and closed by a developer at Google who stated that “the development team has implemented this feature and it will be available as a part of the next public build.”
The next public build referred to is probably Android L, since this looks likely to be the next build that is issued to the public. Multi-user support has been available since Android 4.2, but was limited to tablets.
Are you looking forward to multi-user support on your phone?