I agree I believe an action combat system is doable. As an MMO veteran since the days of AOL's NWN to now lag exist, it affects play no matter the style of combat. I think most of us are tired of tab target and clicking. At least I think most are.
I believe the action style combat can cater to all playstyles non-twitch and twitch alike. I mean strategy can be involved at all levels to that more cerebral players can have an advantage in a fight just as a twitch style player. I mean fighters in the world are more physical than wizards who are cerebral. The game play style should reflect this.