For me, the most anxiety-inducing change that came with patch 5.0.4 was the prospect that I would have to find a replacement for my beloved RealUI -- the previous author Nib stated that he/she would be unable to continue its maintenance, causing hundreds of minimalistic UI lovers to suddenly cry out in terror. Thankfully these pleas were silenced as someone else offered to take up the reins and pushed out a new revision just in the nick of time.
Before giving an official verdict on any of these changes I wanted to raid a bit to see them in action. Unfortunately I've had to resort to sidelong glances at Dragon Soul as my guild is finishing up T11 metas and mounts for everyone before the expansion closes. I did, however, get to down heroic Ragnaros again for another pretty bird and run a handful of Hour of Twilight heroics, so I did get at least some experience.
The redesigned talent system feels more like a wider selection of powerful glyphs than any previous iteration of talents that we've seen before. I remember getting to the Bronze Dragonshrine in End Time and someone asked if I could CC one of the dragonkin. I was in the middle of typing out, "I'm not specced into Repentance, sorry :(" (complete with sad smiley face so they knew I was truly sorry) when I realized that I could just open my talents, unlearn Burden of Guilt and pick up Repentance in like 10 seconds flat. Similarly, on a quick jaunt through heroic Firelands we arrived at Alysrazor without much of a plan for slowing down the meteor when I remembered I could unlearn Repentance and pick up Burden.
Of course, being this flexible comes at a price, and that price is straight cash. As I struggle not to finish that Randy Moss quote, think about whether you agree with the gold requirement for changing talents. On one hand, it's a pretty effective gold sink as anytime anyone wants to change a talent they will need to pay a nominal fee. On the other hand it seems a bit outdated to hold on to one reagent when tossing out most others. We can save that discussion for another time, though.
I have to admit, tier 5 for me is usually between Holy Avenger and Divine Purpose. Sanctified Wrath just isn't producing comparable numbers in sims and it doesn't really have its own niche in which to excel.