no ETA...
I've been looking at Punit Soni's Google + account, there is no ETA.
He told me that we have to wait for qualcomm to update the binaries and drivers for the Soc/radios, and then they will update, first unlocked/dev editions, then branded ones.
there is no timeframe, but samsung will update the sgs3 (the US version has the same chipset) in late Q1
http://www.android.gs/samsung-galax...e-to-arrive-by-the-end-of-march-says-insider/
as far as ive seen, they will bring kitkat to last years phones, then 2012 phones.
so IMO, i think it will be april/may if you have a phone on contract...
alas, i think its the last update it will receive.
i asked him if they would dump the kernel like they did on the moto x and moto g and they will do so for the xt926 developer edition.
so once KK rolls out, expect better custom ROMs...