Despite the fact that the SGS4 is the predominant Samsung flagship currently, and we are already hearing rumors of the SGS5, there are still millions of users out there still sporting their trusty Samsung Galaxy SIII. For owners of the LTE (GT-l9305) version of that device, you will be pleased to know that the Android 4.3 Jelly bean update has started rolling out to that device. Even the the rollout has started, it will go out in batches so your particular device might not get it for a few days.

Also, keep in mind that if you are locked to a carrier, it will likely take even longer to get the carrier vetted update. Here's a quote with a makeshift changelog below,
- TRIM Support (Makes the device much faster)
- Core UI elements updated to the ones on the Galaxy S4 (Galaxy S4′s theme all over)
- New Samsung Keyboard
- GPU drivers have been updated (Higher GPU benchmark scores)
- New Lockscreen: Multiple Widgets, improved ripple effect than Android 4.1.2, ability to change clock size and set a personal message
- New Screen modes (From S4): Adapt Display and Professional Photo
- Daydream
- Driving mode
- Actionable notifications
- Move-to-SD-card feature
- New Camera mode : Sound and Shot
- New Additions in Notification Centre
- Completely revamped Settings UI (Tabbed interface – Exactly like the Galaxy S4)
- Implementation of Voice controls (Let’s you control various parts of the phone using voice commands – Galaxy S4 feature)
- New Samsung Apps: Calculator, Clock, Contacts, Gallery, Music
- Full screen Samsung apps
- New S-Voice (from Galaxy S4)
Sound off if you have your update yet.
Source: SamMobile