To offer an alternative experience to LG's, I reckon there's some merit in the losing bonus point. I well recall the Tahs/Clan match at the SFS in 1996 when the Clan were 11 points down at the 80 minute mark as they were attacking the Tahs' line. The boys from Dunedin, who were obviously going to lose, kept the ball alive for God knows how many phases and eventually scored a try some two minutes after the siren. It was great theatre. On another note, a couple more losing bonus points would've been worth gold to the Force this year.
The prospect of losing bonus points gives the trailing team a shitload of incentive late in the game. I vote for keeping it.