Okay, I didn't mean for that to come out so cynical, the new challenge rules make it very cinematic for characters (minor and major) to step away from the ranks and duke it out old-school. But if GW went to the trouble of creating such a cool scenario for us to play out, why didn't they include some benefit for doing so??!
As far as I can tell, if you refuse a challenge there's a penalty: you don't get to fight and your unit cannot use your Leadership cuz you're a cowardly wuss (or because a cowardly super-character with a 2+ save and power claws challenged a single-wound sergeant with a bolt pistol and a bum knee just because he knew he could beat the hell out of him). So if you decline the challenge there's a bad side. But what if you win, which is of course the whole point? Is there any benefit, other than singling out and killing the best model in the unit? As far as I can see, there isn't one.
You would think after all that pomp and circumstance there would be a prize for single combat. I suggest things like this:
* The victorious unit adds an additional +1, or maybe even adds again the full number of wounds the killed combatant had, to their combat resolution total for determining the winner of the assault. So if a mighty chaos lord with 3 wounds was killed in single combat among the violent press of bodies, at the end of the phase add the number of wounds dealt to that dead lord, plus his 3 original wounds, representing the great achievement of slaying such a powerful character in a duel.
* The side of the winning combatant cannot be routed by a failed morale check if they end up losing the total combat. Let's say your side wins the challenge but loses the combat in total wounds: you may lose but no morale check is needed -- having won the combat was a bolster enough that your men fight on regardless. They count as having tied the combat and the fight continues as normal next round.
* If the total combat goes on into a second round after the challenge has resolved, the winning side counts as having Preferred Enemy for that next round, having been bolstered by the victory to press ever further into the fray.
SOMETHING. It just seems too cool an event to have no real value or benefit in the game.
Any other ideas out there...?