Last time I heard that spefically Korean MMO's still do decently enough in the American/European market.
About that Arcade MOBA (which will never get ported anyway), we don't really know if any of the games Sega makes in Arcades are good...until they make lots of money, which means it's addicting, and in some ways good I guess.
Anywho, yeah the Online market for these games is tough and crowded. Tough I think Sega's got unique enough content to stand out...
And of course, Sega in the West has never really been proven to handle an Online games in a comptent way. In Japan tough I think, they are pretty good at it.
Square Enix announced Gunslinger Stratos (Team-based shooter) and Lords of Vermillion (MOBA) for PC...and Namco Bandai has Rise of Incarnicates going currently, and some F2P (probably Action-RPG) coming out for Wii U.
It just got me thinking how the Japanese market is changing on PC, and what Sega could/will do in the future. It's interresting.