Each model has different celluar radios in them are depentant upon where in the world it comes from and the local carrier. Even in the US we have at least two of these models across different carriers. It does take some time for LG to produce the update and then submit it for carrier testing to ensure it functions properly. Most likely the international model of the Optimus G has received the update and localized verisons are still forthcoming.
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.
LG says it doesn’t know when the KitKat update will be available for the Optimus G — or whether it will come at all.
I had the Optimus G...great phone if you don't care about receiving updates (or having them work right).
I bought it right before the Jelly Bean update 4.1.2 was being rolled out (April '13) and had nothing but problems with the phone after that update. I traded up to HTC One and I'm LOVING IT! Now with the G2 as LG's breadwinner (followed by Optimus G Pro), that will receive the bulk of OS update support and the Optimus G probably won't see 4.4 until at leastlate March or April
I've studied and learned a lot about the software update process in 2013 across all carriers and manufacturers. Due to LG's own UI (same with all manufacturers) that they throw over stock Android, and carrier bloatware, you can expect at least 6 months from the time Google releases an upate before you'll see it.
The KitKat 4.4 rollout schedule is much more aggressive, but only by Samsung and HTC (so far).