I see on every martial arts forum including this one the debate about martial art versus sport.  I must say that it is handled much more pleasantly and in more a spirit of discussion on this forum than I've seen anywhere else.

But why do we care?  I see MMA guys trash talk TMA guys and make statements about how TMA doesn't work in the ring, all fights go to the ground (I disagree) and other such commentary.  Then I see guys within TMA look down their noses at the sport/tournament oriented taekwondo, making similar comments regarding sport/tournament vs. 'real' fighting. Does the sport aspect in some way diminish our ability to defend ourselves?
   
One thing that is to be considered in the whole SD/sport thing is this: nobody in the west differentiates boxing in terms of sport or self defense.  We all acknowledge that anyone attempting to mug Evander Holyfield is very likely to end up in the hospital.  We don't look at Floyd Mayweather and question whether or not he can defend himself.  Guys who find themselves in fights with golden gloves boxers nearly always regret it. 

TKD is primarily a striking art.  It has offense and defense built into it.  While I do believe that a TKD class should have some focus on 'real world' self defense and training on how to deal with an armed assailant, in no way do I think that a highly skilled tournament competitor is at some sort of major disadvantage should they be attacked.

In WTF class and tournaments (can't speak for others), we spar, nearly always full contact.  While we do wear padding, we still get kicked/punched off armour in a match and even with padding, there are knockouts.  Consider that a kick from a skilled taekwondoin packs the equivalent force of Barry Bond's swing at the ball with a baseball bat.  Even with padding, nobody would casually blow off getting hit with a baseball bat.  Yet we practice defending against such blows regularly.

I think that the debate about sport/art in terms of superiority of one over the other is a rather tired one.  People take taekwondo for a lot of different reasons.  Each of those reasons are valid, and while all may not be for self defense, all who take taekwondo are going to emerge more able to defend themselves than before they took the class. 

Daniel