I've ran with a few holy paladins since wotlk came out, and I'm still waiting for them to go OOM in 5 and 10 mans... unless you are spamming holy light (bad idea) there is literally no reason for holy paladins to OOM in 5 and 10 mans. As for other healing classes, sure Priests and druids have it a bit better, but shamans do go OOM alot more frequently, and even then it's only on longer fights from what I've seen. The change to divine plea is there to offset the changes to the 5 second rule, and also as a nerf to holy paladins in PvP. (The blues mention that divine plea was added mainly for ret and prot to regen mana, but was too powerful in its current form for holy). They've also mentioned that they are nerfing mana regen all around because it's near impossible to run out of mana (in raids) unless you activley try, and even then with judgement of wisdom DPSrs cannot run out of mana! Blizzard has stated they want players to play while thinking about mana conservation, just like warriors/druids/rogues/DKS have to think about thier DPS resource conservations.
With DPSrs never running out of mana as it is (except on extremely long fights), they probably do not want wisdom, hence Kings is the superior buff. If a ret is in the group, he should be giving physical DPS Might, not kings, and why should the ret paly spec kings just to satisfy your selfishness of not specing it...? it's in the prot tree, so prot should probably pick it up. The 3 prot palies that I run with regularly and semi regularly pick it up, and they have no issue with threat/mitigation, and that includes when they were still in blues. This change means they have 5 more talent points to spend. I could agree with your argument if they changed back kings to 1 talent point at the first tier in the tree, but in that case, why not make it baseline so that you wouldn't be forced to pick it up? (note at 1 talent point it would be a REQUIRED talent for all specs, and blizzard has stated they are against required talents, and now they can balance stuff around the assumption that kings is available). Note that kings is probably the MOST powerful overall buff in the game, why wouldn't you want it baseline? It gives you more utility, and you only need to assign buffs once (with paly power), and if you have 2 druids of different specs in 5 mans, just give them both kings: they both benefit from it! (making your life easier). As for the hunter whining about kings... did you give him might instead? (note: might is the better buff unless you are SV and half decently geared, even untalented might). If you told him that you didn't have kings and he still whined about it, you can do one of three things, ignore him, don't buff him period, or boot his whiney ass from the group. (note that I usually ask for kings myself if there is a paly, and if they say they don't have it, I ask for might or wisdom depending on if there is a DPS warrior or not).
Prot isn't really good in PvP (well, they do have their specialites in BGs - Flag carrier of OMG die already), so the shield change is a BUFF in PvE, and with you screaming at the RP invalidity of the excorism change, this actually makes sense from an RP point of view.... getting hit with a shield in the face would make me probably stop my spell casting for a bit. And having abilities balanced around RP... lol, when has blizzard ever done that. Excorcism is still going to be better against undead/demons than others (it will be a guaranteed crit), and it will effectively balance ret paladins in PvE for future content as Waldy has said. If you want RP justification, just assume that all beings have a hint of evil in their souls (and having a hint of evil, doesn't mean that you are evil, it doesn't necessarily mean that you are good either).
The changes to ammo.... now thats sexy, that will save me about 100+ gold a week. and the talent changes for Hunters are nice... not great but nice. I just hope they get around to implementing SV 41 point talent (which they have promised since 3.0.0), which used to be a 21 point talent. overall I'd say the changes are in the right direction, with DPS classes doing roughly the same DPS, healers having roughly the same mana regen/healing abilities (although, yes, holy doesn't have an AoE heal... but they have bacon which is A very nice talent that no other healer class has an equivalent), and balancing of the tanking classes seems in line. (druids got what they asked for, another stat to lookout for on gear (crit), unfortunatley for them it looks like they will be slaves to the RNG. I'm wondering if this shield will apply to magic damage, if so it probably is a nice buff depending on how much they nerf armor. and it will also mean that druids have more room to hit armor cap come with the new content).