If you've been keeping tabs on the Paladin changes lately, you might've noticed one thing that jumps out -- Spiritual Attunement will no longer be a skill but a talent deep in the Protection tree. Essentially a mechanic designed to help Paladin tanks keep their mana up, it was also key to Retribution Paladins' mana regeneration as it works synergistically with Seal of Blood / of the Martyr, the primary Retribution Seal.
Of course, if Spiritual Attunement being removed from trainers, the self-damage of Seal of Blood becomes little more than a gimmick and an inconvenience. It also tended to invalidate one glyph, which was the Glyph of Seal of Blood. If Spiritual Attunement is deep in the Protection tree, then the glyph becomes aimed at tanks... who don't use the seal. When players pointed this out on the forums, Dresorull replied to test it out in a future build (I still had Spiritual Attunement as a skill on the PTR) and locked the thread.
In a related post, Ghostcrawler lays out Blizzard's intentions for Paladin mana regeneration, saying that Spiritual Attunement is critical to Protection, but they "don't actually like Holy and Ret having (it)". He explains that such a mechanic depends too much on the encounter and gave Patchwerk as one example where SA won't return mana to anyone but a tank. He notes that Blizzard would still like to tune Paladin mana regeneration -- Holy through Illumination and Retribution through Judgements of the Wise.
When I first read about the change, my first fear was that Retribution mana regeneration would take a hit. And it will. But Blizzard clearly knows this and either planned for it or have plans to compensate. I'm curious to see how they will "tune" Illumination, which has been nerfed several times over the course of the game. It'll also be interesting how they will deal with Seal of Blood, whose feedback damage only makes Retribution Paladins a healing liability in raids. I really like the feedback mechanic, but it won't make any sense without Spiritual Attunement. Will Blizzard keep the damage now that SA will be too deep in Protection for Retribution to reach? Stay tuned. Or I should say, stay attuned.
Edit: Changed a sentence to indicate that it was Dresorull who locked the thread, and not Ghostcrawler. The QA team locking threads on the Test Realm forum is standard procedure once the report has been noted by a member of their team. -Alex