Ahh, patch day raiding. So much troubles. My raid UI was completely messed up with groups being stuck in the middle of the screen. If you have that problem, type /reloadui until you can click on them, then close them immediately. After doing that several times, things got cleaned up nicely.
Also, my UI scale seems off. Everything seems very slightly larger, and things are not fitting together quite perfectly.
I think the new sound engine is working well. Everything seems to sound a little bit better to me, and the game performed slightly better. As well, there are new sounds scattered about. I haven't tried the Voice Chat yet.
The buff changes are extremely nice. 10 or 30 minute buffs are great. Also, the changes to pet buffing are really nice. If you're wondering how pet buffing with greater blessings works, it goes like this:
1. Hunter pets share blessings with Warriors. Buffing a warrior will hit all the warriors and hunter pets. The jokes just write themselves.
2. Warlock pets share blessings with Warlocks. Buffing a warlock will hit all the warlocks and their pets. The only exception is a phase-shifted imp. If the imp is phase-shifted, it will not receive the buff.
This is a great change, as it means that the pets get buffed without any extra effort on the part of the paladin.
The nerf to Blessing of Sacrifice was muted. The cooldown was reduced to 30s, which is the duration of the spell. So that means you can still use it in PvE on tanks. It is still useful in PvP, but it can be countered by Purge.
I haven't tried out the new Seal of Vengeance yet, so I can't comment on it.
Other than that, the patch looks pretty decent. Many people have commented that it's not worthy of being a "full" patch, as it doesn't have a lot of new content. However, I think introducing a new sound engine is a big enough change that it warrants its own patch.