I've actually been mulling over many of the same ideas and concepts myself. I envisioned a combat system where you would move your character using WASD, a la first person shooters, but the camera would follow over the shoulder at some distance. The mouse would be used for viewing and mouse buttons would perform attacks. This is essentially the same as the Star Wars:JKIII system in description. However, my idea was to incorporate a bit more point and click RPG into the mix. You can click to move/attack a target at a certain location. Strafing and moving modifies your position for things like dodging and if you need to lunge at your opponent. The camera would adjust based on where you click to move in this case, the mechanics would have to be intuitive so that your view wasn't constantly rotating but the movement keys (WASD) would always be axis alinged. This would allow for relatively complex maneuvers in combat - you can change targets or points of reference by repositioning the mouse and strafing/dodging relative to a new location. You can cast spells/ranged from afar and also get into melee to beat on your opponent. The movement keys would come into play especially in melee - if you click on an enemy who is in melee range when using melee attacks, the movement keys influence your combat actions. This combined with a sort of limited mouse gesture system - if you click you stab at your opponent, if you make a sort of slashing motion, your weapon follows you. I like to think of it as a more fluid and interactive Diablo II combat system.

Personnaly, I've thought that it would be easier to use the arrows to move the player, and then the numberpad to give the directions for the arms movements. In addition, you could use the RIGHT-CTRL to make parries, and the RIGHT-SHIFT to make thrusts, the basic use of the number-pad being the slash. Maybe you can use ALT-Gr to use the shield in the right quadrant or to bash your opponent.

But that's just an old idea. maybe someone can refine it further...