I found this little line very interesting in the patch notes:
Blizzard damage has been increased by 70%.
I've noticed a decrease in utility for Blizzard the deeper I've gone into Cata. For what it does --and AoE attack that will proc Fingers of Frost and other goodies-- the damage has been really lagging behind most of a Frost Mage's other attacks. The only times I've used it in instances I've done it more for the procs than anything else. And now, Blizz seems to be putting some of the damage back in.
Another big impression is that Arcane Mages are getting some good buffs to bring them more in line with Fire and Frost. Based on the DPS charts I've seen, Arcane has been lagging behind Fire and Frost in raids, and Blizz is moving to correct that.
As for Paladins, not that much is in the PTR, other than Illuminated Shield getting a longer duration. I'm sorry, but Righteous Fury persisting after toon death isn't anything to cheer wildly about.
Now this little note about the LFD tool is very interesting:
The Dungeon Finder now attempts to avoid putting damage-dealing classes with the same armor type in a group.
Apparently that wasn't always the case, but I guess that means that DKs, Warriors, and Pallys will be more rarely grouped together as DPS. Same goes for the cloth armored Warlocks, Mages, and Shadow Priests, and for leather/mail armored Rogues, Hunters, and Druids. Of course, "try" != "will", as I've been on a four Pally run through Gnomer before.
One final note: I found this entry in the Hunter section truly amusing:
Glyph of Mend Pet is now Glyph of Greater Proportion, which increases the size of the pet slightly.
All I could think of when I saw that was the line in Blazing Saddles: "Excuse me while I whip this out!"
EtA: One huge win for the leveling crowd: BC Instance maps are now in the 4.1 patch!! Woo!!