Reputation grinding is something of a mixed bag in the World of Warcraft-- some factions have many options for the player who wants to gain rep. Most of the new factions in Burning Crusade have quests, turn-ins, and various instances that all award rep. Others (especially those that existed pre-BC) are more difficult, requiring hours upon hours of grinding away on specific mobs that provide little return, as anyone who's ever gotten exalted with the Wintersaber Trainers will tell you.
Not all factions provide rewards that everyone will need-- if you're anything like me (and, I think, most players), you'll pick and choose which factions you want to grind. For at least one person, however, the goal was to hit Exalted with all available factions.
Tombom, from Cho'gall, is exalted with 36 different factions (37 if you count switching from Scryer to Aldor), including Darkmoon Faire. I'd be lying if I said that this didn't make me feel bad about neglecting some of my own reputation goals, but it does inspire me - if a Disc / Holy priest can do it, why not me?