I say no, it is not needed, I really love SWTOR, and some of these same people suggesting a combat log, are the very people I left another mmo I enjoyed, because the developers didn't have a back bone enought to tell the community NO!
There is no need for a combat log, and the game works just fine without it, trust me imo anybody stressing otherwise, really are customers better off left for EVE or WOW or some other game that is stale and littered with people less about having a good time, and enjoying THE GAME, and more concerned with ego. Again I say NO!