French telecom operator SFR has announced that LG will be releasing Android 4.4.2 KitKat update for SFR variant of Optimus G this summer. This upcoming update will take the phone directly from Android 4.1 to Android 4.4. This is certainly a good news for Optimus G users on SFR but there is still no confirmation about other regions, however it seems likely that Optimus G in other markets will also get KitKat update.
Official change-log is not available at this moment but there will be significant changes due to the big Android version jump. LG will most likely be porting the user-interface present on LG G2 to Optimus G.
Originally introduced in August 2012, LG Optimus G first ran on Android 4.0 but was later updated to Android 4.1. When released KitKat will be the second major Android update for this smartphone.