I feel sorry for Retribution paladins. Every beta, Blizzard overpowers Retribution, and ends up scaling it back for live, thus disappointing all the paladins who are watching eagerly.
WotLK appears to be continuing that trend. Retribution is sick right now. I'm testing on Quel'Danas, and level 70 mobs die instantly. Judgement, Crusader Strike, Divine Storm, dead mob. I'm not even in that amazing gear. I'm in T4 with a Gorehowl. I'd hate to see what the T6/Sunwell people are capable of.
So far, Ret is extremely good for soloing. Judgements of the Wise returns a fair bit of mana to the paladin. Basically, right now there is close to zero downtime with Retribution.
The biggest Retribution news out of beta are the massive 15K - 20K Judgement of Command crits Retribution is capable of. This is not an exaggeration. My best crit so far was 12.5K, and that was without trying. In better gear, pop Avenging Wrath and trinkets, and I can easily see coming close to 20K.
What's really weird about these crits is that they are somewhat controllable. The Art of War is procced off a Crusader Strike. So you wait for Art of War to proc, then stun and Judge Seal of Command. And since Fanaticism gives you +25% crit chance, that puts the chance for Command to crit at over 50%. Between the Art of War proc and Fanaticism, this burst is oddly reliable.
All in all, I think Retribution is headed for a nerf. And there will be much wailing and gnashing of teeth on the Paladin forums.