Blizzard has a very interesting post on Tol Barad today. It turns out that Blizzard deliberately made it easier to defend, because they didn't want it to just flip sides, and to make capturing it a more momentous event.
Of course they made it too hard, and they increased the rewards to 10x for the attacking team. Which promptly led to win-trading to maximize honor gained for both sides. Blizzard recently reduced the honor for winning, and Tol Barad seems more or less back to normal.
On a side-note, its interesting to note that the reverse scenario does not produce win-trading, while still encouraging people to fight hard. If defending is harder than attacking, but defending has 10x rewards, you don't get win-trading. This is because winning as defense keeps you in the defensive position. But it doesn't accomplish the goal of making captures a momentous event. It makes a successful defense a momentous event.
First, I really wonder if fiddling with rewards will ever produce the result they want. Can motivation to win really outweigh the mechanical advantage, especially in an ad hoc group?
A commenter at MMO-Champion described the situation as two extremes: either the defending faction always holds Tol Barad, or Tol Barad switches every battle. Blizzard is aiming for something in-between. But it seems like this genre always ends up hugging one extreme or the other, so I'm not sure if Blizzard can hit the mark.
My solution to Tol Barad, given Blizzard's goals, is to leave the map weighted in favor of defense. Then I would add a stacking buff (a la ICC) to the attacking side, Attacker's Resolve. Each time the attackers fail to capture the island, the buff increases. When they do capture the island, the buff resets and goes to the other faction. The amount of honor the defense gets for winning would scale with the buff.
What this does is ensure that eventually the mechanical advantage goes from defender to attacker. It might take a while, and the exact point where the switchover happens is uncertain. Meanwhile, the defenders are always attracted by the honor gain, especially when the buff starts to get high. That means that more attackers can join the battle, since it's one-for-one.
But the defense still needs to win to gain the honor, they can't throw the game, and the attackers are less likely to throw the game because the defenders would remain in the desired position.
(It's possible that a server would come to an agreement to always switch when the buff reaches a certain point, but it's almost impossible to prevent that without making the reward zero-sum. You could remove the reward increase, but that might encourage defenders to stop showing up after a certain point.)
Basically Tol Barad would boil down to an equation. When does:
Attacker Skill + Attacker's Resolve Buff = Defender Skill + Defender Map Advantage
It might be a different point for each server, or be different for different times of the day. But eventually, the attackers would win, and the island would change hands. There would always be hope that this battle would be the tipping point.