Everyone likes concrete exit strategies, and no one likes vague, endless wars. So how will we know when the War on Terror is over? I think there are a few specific events that must take place before we can make a declaration of victory.
1. Elimination of radical Islam as a political power. This means the Wahabi rulers of Saudi Arabia will have to go, the mullahs in Iran, the crazies gaining power in Pakistan, the Ba'athists in Syria, &c. They aren't united under Islam in the same way that the USSR was united under communism, and so it won't be as straight-forward as when that evil empire collapsed. Nevertheless, just as communism was eradicated as a world power, so too must be radical Islam.
2. Capture/elimination of terrorist leaders. You know who you are. We have to track them down and take them out of circulation. Seize their assets, break up their organizations.
3. Resolve the Palestinian problem. There are a lot of ways this can play out; I would prefer that the Palestinians all go back to Jordan, Egypt, and Syria where they came from and that Israel be left alone. However, even if the situation is resolved with Israel being utterly destroyed, this condition will be satisfied.
4. The above goals all play a role in leading towards functional Arab democracies. Capitalism, freedom of religion, freedom of speech, and free elections will ultimately do away with the vestiges of the Islamic death-cult, and hopefully leave in its place a vibrant, peaceful Middle East.
As SDB has pointed out several times, our government can't just lay out these conditions and make them public. Hey Saudi Arabia, you're next! Meanwhile, help us round up these terrorists, please.
Then again, maybe they will lay it all out. I love you, Condi.