This trick probably won't work on a Cleric or anyone else who has a good Will save.
The typical vampire is a fighter, with a base Charisma of 8. Even after the vampire bonuses, and with his low HD compared to CR (2 less than CR usually), the save DC won't be unstoppable.
Vampire sorcerers, on the other hand, are just plain sick. Bonus to Charisma score really pushes up that save DC, and the hp gain will have your front-line fighters tearing out their hair - unless they're ordered to stop.
If you know you are going to fight vampires, get something that protects you from his gaze attack - like Magic Circle against Evil (which will also give you an AC bonus, cool, huh?).
Get your cleric (who made his Will save) to turn the vampire. Even with turn resistance, the vampire's effective HD are only about it's CR, so the cleric will turn it more easily than they can turn a zombie of the same CR. Then shoot it with blessed crossbow bolts, get your druid to toss magic stones at it, etc.