I was told by this Korean developer (possibly Nokia employee as he sounded like he knew quite a lot about the future PR releases) told me that Korean font isn't provided with PR 1.0 but it is included in PR1.1 although "hinting" is not supported so the fonts won't look as pretty as they can be. He said it will be supported in PR1.2. (he said this with zero doubt and certainty)

EDIT: He confirmed that he works for Nokia as a N9 Software Engineer.
(Wow. Glad there is a Korean in there trying to make the N9 better! )

He made a Korean input engine and keyboard for N9 using a modified meegotouch framework. He sent me the files and I was able to install meego-imengine-hangul deb file. This allowed me to choose Korean in the input selection and now I can switch back and forth between the English and Korean keyboard layout by swiping the keyboard as normal.

But the input engine isn't complete. It breaks the Korean characters in certain use and doesn't type it into the app directly. He did tell me that he made this keyboard for pre-PR1.0 release of Meego Harmattan and worked perfectly but it became broken with PR1.0 so he is working to fix this.

Once I get a working version from him, I will update it here with it.
Or he might just release it on OVI store. Time will tell.
But for now, I can type Korean on my N9 although it's quite annoying.

Here's a screenshot from my N9: