I think that the paladin is a questing class.
Like Don Quixote the Paladin should be able to declare/establish that he is on a quest and get quest bonuses.
Maybe at first level he needs 24 hours to prepare, but then he can declare a quest and get bonuses for himself. At a higher level he does not need as long to prepare. At another level he is able to get bonuses for the whole party for the duration of a quest.
This gives the DM a chance to add flavor to the campaign, because the paladin may learn during his meditation/preparation that there are certain rules he must follow for the duration of the quest, and they could be fairly creative.
Maybe at early levels the quest can only last for a day or a week, at higher levels he could declare a quest that may last for the rest of his life, such as following Lavinia's trail into the abyss and not stopping until she is rescued.
What should the quest bonuses be? Maybe will saves, saves against fear, maybe damage reduction. I don't know...but we should have some game mechanic that honors the questing aspect of the paladin and helps fill out the dead levels, and gives players who play paladins more incentive to interact with their God, to swear oaths, dedicate themselves to quests, etc.
Excuse the repetitive post but I am sort of thinking out loud.
This will make playing a paladin more fun, and not complicate things too much.