Here is a post from Eyonix about the upcoming stat and system changes to our gear, gems, etc. in WoW Cataclysm: [Source]
A couple key things to note concerning Retribution Paladins:

Reforging will allow re-distribution of certain stats.  Certain stat changes will not be permitted, such as Stamina to Strength.
Ret Paladins will be getting mana through other means, no Intellect on gear (a given).
Armor Pen is out, will be converted to crit or haste.
Ratings will be much more difficult to cap in Cataclysm.  This means no easy hit caps.
Weapon skill is gone.  …

Haste vs Armor Penetration.  Which stat is better for Ret Paladins?  There is a alot of argument and confusion over which stat seems to be better for a Ret Pally.  You can make very solid cases either way, but nothing is actually set in stone.  There ahave even been some conflicting comments here on my site as well.
After a couple weeks of research, playing around with Rawr, checking the EJ, WoW, and retpaladin.com forums, it would appear the general concensus is that Haste is still better than Armor Pen, even …

Ret Paladin Hit Cap at Level 80
The hit cap for a Retribution Paladin at level 80 is 8%, or 263 Hit Rating.  At level 80, 32.79 Hit Rating equalys 1% hit.  Hit Rating reduces your chance to miss with white, special, and judgement damage.  Exorcism and Consecrate are spells, and thus they fall into the spell hit table.  They will have the chance to miss at times, because we give spell hit absolutely zero priority.
To maximize DPS, each Ret Pally should have their hit capped.  With 3.3 out and the …

Off-speccing protection is one of the many benefits of having a retribution paladin.  It is extremely useful to have the ability to jump into prot pally mode for raids or soloing purposes, and it is one I recently switched to myself.  With a desire to tackle more Molten Core and Karazhan content solo, I decided to change my off-spec from holy to protection.
Now, retribution is clearly my favorite spec to play, but the benefit of being a paladin is that we can switch between all three roles in the World of …

Playing as a Retribution Paladin in the PvE world far exceeds my expectations of most other classes. Our burst damage is still top notch, and we can just about nuke any non-dungeon mob in a couple hits. The down time for our class is next to nothing thanks to a couple very efficient and optimal mana and hp regeneration talents and abilities. And we can easily switch roles to healing or tanking if the need arises, making us valuable assets to any function of the game.

This is a compilation of …

Patch 3.3: Ret Paladin Gems is current for Patch 3.3.  No new changes with our gems and gem usage as ret paladins.  Hit cap is first, then you will be gemming for solid strength from that point on.
As a retribution paladin, your gem choice is going to be quite limited. Really, you should only be gemming for 2 stats.

Hit Rating
Strength

You could technically gem for expertise if you wanted as well, but hit and strength are the most important.
That said, most gear now has plenty of hit rating on it, so …

I have further updated the talents page. Hopefully the information is a bit more comprehensive.
Khor

The sweat and blood is spent. The days of played time are over and you are now level 80! So what’s the first thing on people’s mind as they stand at the plateau of 80-hood? Gear. How can I gear up as quickly as possible?
I have created my list of options, with my preferences
Well, first, be warned this list might not be for those with empty pockets. It costs gold to grab those coveted BoE items, and on certain items, lots of it. However, …

WoW add-ons are not exactly my favorite thing. Sometimes I feel like they are just too much to keep up with. However, some are vital to gameplay, and even I will admit that. As I play retribution paladins most of the time, my add-ons and mods are very similar. I have compiled a list below, but notice I have no major UI add-ons. I use the vanilla UI. Call me old school, but it’s the best for me.
As a Ret Paladin, there are certain …

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Retribution Paladin Talents
Current for Patch 3.3 and Patch 3.3.2

The Ret Talent Tree seems to change with each content patch, as our DPS and damage output is modified by talent and ability changes. Retribution Paladin talents will primarily focus on the Retribution Tree, while dabbling in Protection and Holy. It seems to vary, depending on raid encounters, how far we dip into the other trees, and as of Icecrown Citadel raiding, we are currently only dropping 5 points into protection, …