Please see this page for Android Studio Stable versions.
January 10, 2017: Android Studio 2.3 Beta 2 includes a several updates, bug fixes, and performance improvements.
Note: Android Studio 2.3 Canary 1 had issues in it's patching system, so a full download is needed when moving from Canary 1 to Beta 2. Android Studio 2.2.X should offer patches from major stable releases. All other users will need to download the full release to update.
The release is available in all channels, so you can check for updates via Help > Check for Update... (on OSX, look in the Android Studio menu). This will download and install a patch rather than download a full IDE image.