You can see the ratings for yourself here: http://www.grb.or.kr/Statistics/GameStatistics.aspx by searching for "Diablo III" or decisions made on 2012-01-13 (If you don't have a built-in translator, please goto http://translate.google.com first before visiting these URLs.)The rating on Diablo III only shows "Violence", but there is no "Gambling" in the game. This seems to also indicate that the RMAH has been removed entirely.
Approved in SK on Friday the 13th by the way. :)
Based on various news articles, it sounds like Blizzard might have resubmitted it again, but with the RMAH completely removed. Based on the translation, it says that cash transactions between users were not subject to review because they were not implemented. It also says that if the service modification is made in the future, it's not subject to reclassification but it will face Law Review and other associated organizations. Basically, it's not the GRB's problem anymore if Blizzard decides to implement the RMAH.
I'll need our Korean translation expert to confirm this translation though.
If this is correct, it appears that Blizzard might have resubmitted another version that completely excluded RMAH (i.e., not even the B.Net Credit system) some time ago, knowing that this would finally fully approve the game.
* UPDATE:
According to the Korea Times, Blizzard did in fact submit a 3rd version of their submission, but this time without the RMAH entirely. There's no word on when it was submitted, but I'm guessing it was shortly after their 2nd submission (when they requested that the RMAH remain, but only for B.Net credit.) Which would have put it before this tweet too. :)
Korea Times also said that if it was added as a software update, it would face a new round of evaluations. (So it will still go back to the GRB, and won't directly face other government bodies like I originally interpreted from those other sources above.)
I'll see if I can find out when Blizzard submitted the 3rd revision. That aspect is what really interests me.
* UPDATE:
After some forum deletions, Bashiok has confirmed that the RMAH is still in the SK version, but that it will be using only the Battle.net Balance system (which was the second submission, meaning that it wasn't revised again.)
So, I was right, they have an auction house that uses Battle.net balance, which is separate from the gold auction house. There are some details I'm still fuzzy on because the Korea Battle.net balance works a bit differently from ours.There is a lot of confusion about this. Some sources still say the RMAH remains, others claim it has been removed completely.
In any case, it won't be the currency-free option you're looking for.
* UPDATE:
Bashiok's locked thread that contradicted information about the RMAH has now been completely deleted. You can see the original here. There was nothing wrong with the thread to deserve deletion, other than Bashiok's information. So apparently, the Korea Times and the GRB must have been correct and the RMAH was removed completely.