* Photo sphere – for when horizontal panoramas are not enough, take them in all directions (like Street View, incidentally you can submit them to Street View too).
* Swiping keyboard – self-explanatory. Swiftkey and Swype have competition. Can be a substantial time saver if predictive algorithms are accurate enough.
* Multi-user login – this is huge. For shared devices, each user having their own apps, data and customisations are important, especially for kids or shared team devices. Surface RT has this as well.
* Wireless display – Ala Airplay style. Ties in with push on TV and movie content on Play store.
* Notifications improvements – More actionable content within the notification bar. Notification bar now also contains quick-toggles. Split notification bars on landscape, or bring down bar with two finger swipe.
* Security improvements – Including VPN lockdown (for specific apps/content). A play towards more enterprise-friendly devices, especially with multi-user logins.
* SMS warnings for non-authorised messages – For when you install dodgy programs from dodgy places and they try to send premium SMS’s.
* Google Play Virus Checker – Combined with the above, in-built antivirus checker for app installations, a wise move to try to address (sometimes overblown). malware concerns. Play Store’s in-built ‘Bouncer’ malware checker [which runs in a VM] has been known to be fairly straightforward to foil.
* GMail improvements – Swipe to archive, more improvements to a great e-mail client.
* Widgets available from lock screen – Handy, though custom lockscreens already exist.
* Google Now improvements – One of the most handy, but occasionally creepy features of 4.1. Expanded to include more types of cards and Music explorer.