Android has evolved quite a bit over the years. From the very bland and boring interface to what was Android 1.0 and versions to come, it's became fantastic mobile OS with Millions upon Millions of users. And in continuing with that evolution, it appears that Android will soon have multiple user accounts. Now, when you think about multiple user accounts, you may first think about having multiple Google accounts attached to your phone.
That's not what we're talking about here. With Windows for example, you can have multiple user accounts which are great for families. Each user account can be limited to what they can do and each has their own different thing about them as the settings are saved for that user. It seems that Google is aware that tablets, among other devices, are often shared between multiple people.
Not everyone has the same tastes in apps, wallpaper, and so on. Code was found hidden in Android 4.1 Jelly Bean that has to do with multiple user accounts and appears to be implemented across the OS. When multiple user accounts are coming to Android is uncertain, but Google is making it pretty clear that it will arrive in upcoming versions. If you want to read about the specifics of the code, Phandroid has the details here.