The only official info about combat from Larian that I recall being mentioned is that Sektor (who at least at the time was working primarily on combat related stuff) said "In terms of clicking-rate, I personally feel that ED will be much easier on the hands than DD was". This was in the topic
News from the front, after the discussion turned to a debate on combat styles (player twitch vs character stats, the evils of micromanagement, etc, and of course the click rate of various combat systems).
In DD you could hold the ctrl key down to automatically target the nearest opponent to your mouse cursor. I would assume in D2:ED, with no mouse cursor when not in the inventory window, that there would be some sort of automatic target selection (or, less likely, a lot of micromanagement).