Loathe as I was to post about the Tier 10 Set Bonuses, here they are. Note that the Ret Paladin Set bonuses have been swapped and clarified by Blizzard over the current MMO-Champion listing, so I'm pretty pleased I chose to wait:
2 piece bonus - Your melee attacks have a 40% chance to reset the cooldown on your Divine Storm ability.
4 piece bonus - Your Seals and Judgements deal 10% additional damage.
2 piece bonus - Your Hammer of the Righteous ability deals 20% increased damage.
4 piece bonus - When you activate Divine Plea, you gain 12% dodge for 10 seconds.
2 piece bonus - While your Divine Illumination talent is active, your healing spells are increased by 35%.
4 piece bonus - Your Holy Shock spell causes the next Holy Light you cast within 10 sec to have 0.3 sec reduced cast time.
Bonuses are in the testing stage and will remain subject to change for some time.
For my money, the Ret bonus looks pretty good and should change up the rotation slightly, though they may well start to limit what can actually proc the cooldown reset. The one concern with DS will probably remain mana cost, 18% is a big chunk of your mana bar.
It's quite late here so I'll leave it at that.