It seems that we're close to an Android 4.3 reveal as the latest operating system has been leaked for the Galaxy S4. It's still an early testing build, but you can install it if you have the necessary hardware.
Before we get to that, however, let's take a look at what Android 4.3 is and isn't. Google's latest mobile OS is still called Jelly Bean. It still has the same design of previous Jelly Bean builds. On the other hand, it isn't a major upgrade. Instead, it brings a small number of enhancements to the already almost perfect Jelly Bean.
So, what are those enhancements? It appears that the biggest update is the inclusion of Bluetooth LE support. Beyond that, there's been a few tweaks to the camera interface and the inclusion of the share button in more apps. Those expecting a bigger and better Android aren't getting it in this update.
Even so, Galaxy S4 owners can start playing around with Android 4.3 right now. SamMobile has confirmed that the leaked Android 4.3 test build works on both the Nexus version of the Galaxy S4 as well as the regular TouchWiz version. They note that flashing this custom ROM will void your warranty, but that may be a small price to pay to be on the cutting edge of Android.
While Galaxy S4 owners start testing out Android 4.3, the rest of us will have to wait for an official announcement. According to sources speaking to GottaBeMobile, we won't have to wait long. Google plans to unveil Android 4.3 in July with the first build coming to - surprise - the Galaxy S4 Nexus Edition.