Maybe I'm just a retarded monkey but the 4.0 patch felt like it completely nerfed my all-paladin group playing as 4ret+prot. 5 prots were OK but tended to fall prey to the enrage timer/not-enough-DPS problems without overgearing things yet. Having seen some of the post-4.0 subjective reports on boxing DKs, I think I'd probably go with them plus a healer. I've been out for a month so things might have changed enough that they're back to relative parity. Rets have been one of the laughing stocks of the DPS charts for a while unless that's recently improved.