My understanding as of Friday, is that the Eurofighter and the Su-35 have been eliminated, but the F-15K and the Rafaele are still under consideration.
But, in my opinion, the Koreans will never buy the Rafaele, for many many reasons, not the least of which has to do with local politics and allegations of bribery which are not going to go away.
Also, I didn't mean to imply that you might have thought that the Su-27 was in any way equivalent to the Mig-2l, and I apologize if I left that impression. You are obviously someone who knows his way around the aircraft of the world.
I am somewhat more concerned about the Su-30MKK that the Chinese should be receiving sometime soon. Though this Flanker is not as lethal as the Su-37/30MKI, it is still the Russian answer to the F-15E. That imo will definitely turn the balance of power in South Asia. Taiwan will have to do something....either add more Mirage 2000s or F-16s and as you mentioned, South Korea is already looking at the F/X program.