You did that spec WAY wrong >_>
It's supposed to be more like this:
http://talent.mmo-champion.com/?pala...00000000000000
It's not really overpowered tbh; you give up the ability to turret heal really well, and would probably wouldn't be ideal for a 5v5 setting. What it allows you is a very offensive play style, allowing paladin/dps to be more of a 1.5 dps team, sort of the way DS druids are now, or how many resto shamans play in 2v2.
You pick up a LOT of bonus crit and help increase your partner's damage passively too, as well as allowing some decent burst in a JoR + holy shock (with wings up) combo, along with a CC option in repentance. With this build you would be stacking crit/int and spell power, and judging every cooldown to take advantage of your 33% chance to regain 20% max mana.
There's also some room for personal preferance on where you spend your last few holy or ret talents, which helps keep the build from having the cookie cutter feel.
..and I'm not even a paladin.