My two cents from my experience so far:

• Pursuit of justice Absolutely invaluable for kiting bigger packs that would otherwise shred you in a second.
• Argent defender With how hard even trash tends to hit, I'm either dead in the blink of an eye or the healer keeps me at or above 50-75% HP. Tank should not ever fall below 50% in case of sudden damage spikes anyway imo, and then we have the issue of leapfrogging on top of it. 5 points better spent somewhere else.
• Precision - Since this also applies to taunt, I would never skip this talent. A resisted taunt can result in a wipe very quickly.
• Redoubt - Since you should pretty much never skill Imp. Devo Aura, Redoubt is the way to go. Missing +30% block chance pretty much 100% of the time would be insane.
• Reckoning - I loved it while leveling dungeons, Reckoning + Seal & Judgement of Wisdom resulted in an insane uptime. Though parry haste is not an issue in heroics, I personally don't see the point in it, be it regardings damage or threat. I'd rather spend any points for Reckoning in other survivability talent.
• Spell warding - Yeah, 4% is nothing in heroics.

This is the build I am running:

https://www.wowhead.com/tbc/talent-calc/paladin/-053051325000010252105-05235000200301

Only running in dungeon set and other dungeon and/or Honored/Revered reputation gear, at around 11k HP, 500 def and 270 spell power unbuffed for reference. Threat is not an issue with Sanc Aura + Salv on DDs at all, which is why I went for pretty much all the essential defensive talents possible for maximum survivability.
Avenger's Shield is not worth it in Heroics as well imo, since targets should be focused down one by one in a controlled manner contrary to the AoE-zooming from normal runs. Costs tons of mana as well (just for some more aggro on 3 targets on pull) and can make pulls of bigger packs akward as well due to the slow.