I am currently at level 101 (have been playing since release). Since most of my villagers are maxed out, I guess leveling up will slow down until new animals are added.
I don't understand the current animal 'level 20' cap. As I mentioned in the wish-list thread, Nintendo should up the animal/villager level and make the new max reward be a special scrapbook memory of said villager interacting with you, the player. The rotating reward image can be of the villager holding the scrapbook or a video reel, etc.
It's very unsatisfying (and not very motivating) to see those request points fade in the air and the level heart unable to grow when a villager is maxed out. I don't get the logic behind the current limit as they had to have known that hitting level 20 doesn't take very long in this game.