I'm currently DM'ing a ~10th level Evil FR game.
I had 3 players at the beginning, a rogue, a rogue-assassin and an invoker. The pure rogue started out with the leadership feat, and started a small Thieve's Guild in Marsember (Cormyr). The assassin was a character from a previous (non-evil) campaign that came to a halt. The player wanted to keep his character, and so I let him. A little later, a cleric of Bane and a fire genasi fighter joined the group.
In the beginning, the characters wanted to get rich and rob some houses, so I designed a few places they could get into for some money (they usually went for rich widows).
The Night Masks (based in Westgate) wanted a piece of the action in the semi-corrupted city of Cormyr, and they were looking for the tomb of an ancient wizard. Through their contacts and Information Gathering, the party learned about the Night Masks, and attacked their base of operation, which was in the building leading into the tomb. The party killed the Night Masks that were in Marsember and explored the tomb. They got back an evil skull that radiated powerful necromancy. After some research, they discovered that this was a long dead lich's skull, but that there was a way to revive it. They needed the medallion that contained the Lich's soul. The medallion in question had been buried with the hero who slew the lich some centuries ago. The hero's tomb was in the country's Capital, in the Palace, in the Garden of Heroes. They traveled to the capital and devised a plan to get the medallion back while avoiding the stone guardian's wrath.
The anti-heroes came back to their lair to learn that the Night Masks had retaliated, by killing some of the party's low-level operatives. The party found out where the Night Masks were staying and launched a nightly attack upon the manor, killing almost everyone, except the leader which escaped.
The party then proceeded to revive the Lich with a particular ceremony involving the riualistic chanting of necromantic phrases (I actually got my players to chant some evil-sounding syllables

). The Lich was revived, asked why the characters had revived him, and gave them a mission and a reward. The mission is finding and assassinating the last descendants of the Hero who slew him centuries ago (the descendants are a desert hermit living in Anauroch and guarded by the spirits of the earth, a Paladin who now adventures with the assassin's former comrades, now NPC's, and a sultry chaotic shadowdancer who's probably going to have romantic interests with some members of the party, hehehe). The reward was the location of a long forgotten treasure in a marsh. When they went to the marsh, they were ambushed by some lizardmen (who were rapidly eliminated) but some members of the party want retaliation (ie the extermination of the lizardman village).
Yay my very succint and poorly written first story hour!
I guess that for evil campaigns, you're better off reacting to what your players want to do that plan too many things ahead.
AR