Captured big enough market to be ranked above any mediocre wannabe's, opposite to what some people think ,That EA and DICE(the Real Players )cant achieve, its only a matter of time.
And moreover no single game can ever have cent percent dominance over any category or genre with so many titles(read competition) coming up everyday.
Till now COD has been undeclared king of FPS world.But with release of BF3 and tables are more or less turned for both EA And Activision.
Battle is not over dominating any particular genre of games and its specific to the case of FPS coz that genre attracts most attention and most loved genre with casual gamers numberin millions ,looking for it.
So every major publishing house try to make profit by seeking FPSs where as RPG is more suited for hardcore/elite/regular/say whatever gamers and hence in RPG genre ,studios are more focused over delivering quality product rather than just a run of the mill entertainment commodity and thats why we often come across FPS games which people prefer to say "sucks" but hardly any RPGs fails to garnish respect from the targeted Audience.