I know it'd be pretty annoying, but I kind of wouldn't mind if this happened. I like the extra challenge it would bring. Like many have already said, however, it would probably be best if keep to a minimum of 1-2 Revives, otherwise the battle could get tedious. That being said, I would reserve it for characters such as the Champion, the final rival battle(s) [and rematches that follow], and one for each of the Elite 4 members. No one else really needs to have them.
And none for the evil organization's leader. They play dirty as it is. No need to help them in their crimes against the world.
As for the Exp. I don't see why we wouldn't get an extra dose of experience from the revived Pokémon; even just a little. For instance, having the total exp. points cut in half from the first time you defeated it. That could work. The way I see it, experience comes from every challenge you overcome. It doesn't matter if that's a Pokémon you already beat, because then why do we continue to get Exp. from the same Pokémon we knock out in the wild multiple times?