When will the LTE work on T-Mobile in Hungary?

T-Mobile officially supports LTE for iPhone since dec. 1st, but it can't be enabled until Apple makes some kind of software update for the phone.

Does anyone have any information on when this update will take place? How long does it usually take for Apple to make such an update? Will it come bundled with a new iOS update (like 6.1) or as a separate update for this country?