UPDATE: CNET heard from Nokia that it's not preventing Google from rolling out phones with multi-user login, and points out that Nokia doesn't even own a patent for multiple user account. The site says it's unknown why Google only wants to roll out the feature for tablets.
Legit Reviews reports smartphones with Android 4.2 will not receive support for the operating system's new multi-user login feature due to a patent owned by Nokia. Only Android 4.2 tablets will have the multi-user login functionality.
I can't believe what I've just read. One of the cool new features of Android 4.2 Jelly Bean is that it allows multi-user logins. This is just the same principle as seen on Windows, Linux, Unix and many other operating systems and has been around since the dawn of modern computing, around 50 years plus. However, Nokia somehow managed to actually get a patent on this regardless of this prior art, let alone it being such basic and obvious functionality. The upshot is that Android phones are not allowed to feature mult-user logins, while tablets running Android can, as advised by Google in its feature description.