Observations (so far) :
-- Rate at which Goblins spawn is much higher than in previous patches (this is a very good thing).
-- Having the "guest monsters" from other areas is interesting, and it does make the game less predictable, however it also means that (for example) the difficulty curve is quite a bit steeper than for previous patches (a newbie player could easily get killed in early Act 1 Normal if they didn't know how to play and how to do gear selection).
-- Thankfully, haven't run into those !#$*^%#& Startled Witches yet (and hope never to do so) (does anybody know when and where they appear?)
-- I noticed that a few of my characters (particularly their mercs) did not meet the level requirements to use some pieces of their gear (for example I had an A2 Exemplar who was using a T4 version of the Sea Summoner trident, he was fine with it at Level 106 in the last patch, but now for some reason its required level has increased to 108 which means he can't use it until he levels up some more. Was this intentional or is it a bug?
--(Additional) I noticed that at least for the UHM build, somebody in the dev shop has a sense of humor in that "Scourges" are now renamed "Lawyers" (with a nice comment about how they are going to sue you over "copyright"), but they simply don't appear when you cast them (yet... the icon for them is white, not red as you would expect for a skill that is for whatever reason unusable). This particular UHM Paladin has picked Melee Devotion but if this in fact disallows the use of summoned minions it would be preferable for the game notes somewhere to specify so (and what other things do the same). (EDIT) : Realized that the Melee Devotion "Mastery" skill disables summons. I miss the days when we had "LOLsummons"...
-- Continuing on from the 2.7 patch, I noticed that some of my Druids have inherited the "Armageddon" skill, even though they have not put any points at all into the pre-requisite skill trees that you would have to fill out (at least 1 point in each pre-requisite skill) to be able to take "Armageddon". This is probably because the characters pre-dated that patch and the game code had to make a decision as to what happened with their skill point deployments when the structure of a given skill tree changed substantially... but is this kind of outcome really what the devs intended?
More to come as I get used to the patch...