As stated in the patch notes, the mobs hanging out around instance entrances are all now no longer elite. This means the un-instanced parts of Deadmines, Sunken Temple, and so forth.
Ragefire Chasm: I wasn't able to test this out due to not having a Hordie on the PTR. It's 13–20 in 2.2. Anyone know what level Zelemar is now? 16 or 17 would be my guess, based on how they've changed the other instances.
16–20, from 16–22. This was actually my first time ever going there. It looks pretty cool, although a lot easier to get lost in than Deadmines. I liked the scripted event at the end.
: 17–20 in 2.3, from 17–21 in 2.2 Not much of a change there; mostly it's just that Edwin VanCleef got nerfed a level. And check out Rhahk'Zor's Hammer going from a white to a blue.
18–21, from 18–26. The new lower level combined with the better rewards makes it much more attractive. I might not even skip it this time.
: 21–24, from 21–28. I really enjoyed going back here; I'd forgotten how cool and atmospheric it is.
: 23–25 in 2.3, from 23–29 in 2.2. That means Bazil Thredd has gone down 4 levels.
: 24–28, from 24-34. Somewhat surprisingly, Techbot is no exception to the no-elites-outside-of-instances change.
: 24–27, from 24–33. It was my first time there as well.
Scarlet Monastery Graveyard:
30–32, from 30–34
Scarlet Monastery Library:
33–35, from 33–37. This is a new item. Apparently the efficacy scales down with level, so it's no use getting it as a 70.
34–37, from 34–41. Another dungeon for which this was my first time, although I wasn't particularly impressed by it. Obviously, though, sneaking through it and ganking Amnennar doesn't really give me a good impression for how it plays out.
Scarlet Monastery Armory:
35–37, from 35–40. I can't find any changed Armory items, so here's a Library one.
Scarlet Monastery Cathedral:
36–40, from 36–42
: 35–40?, from 35–47. 12 levels is too much for one dungeon to span; I'm glad it's been tightened up. I didn't get to fight Archaedas, because he requires 3 people to summon, but he used to be one level higher than the Ancient Stone Keeper, who's 40 now (used to be 46), so Archae should be either 40 or 41.
: 42–48, from 42–51. This makes it the dungeon in 2.3 with the largest level range. Going through it again gave me the opposite reaction to going through BFD; I now have no desire ever to see the place. Especially the Princess.
: 43–46, from 43–48. Not much of a change there, but ZF was already one of the better tuned leveling dungeons. Doing the pyramid script by myself was...interesting.
(aka Temple of Atal'Hakkar): 47–50?, from 47-55. The reason for the question mark is that I didn't actually get as far as the Shade of Eranikus, because that would have required killing Jammal'an, which in turn requires killing the six troll dudes upstairs. I didn't feel like slinking around ST for that long. But we can be pretty sure Eranikus is either 50 or 51 now, since he was 55 and Jammal'an has gone from 54 to 50.
: Sorry, faithful, I couldn't quite make it through this one. After getting owned a few times in the Grim Guzzler, I decided whoever wants to go see what level the Emperor is now can do it themselves. It's 48–59 in 2.2, so if it follows the same pattern, it should be something like 48–52 now, but I really don't expect they nerfed it that much.
And that's all the dungeons under level 60. Overall, these are some excellent changes. Some much-hated dungeons, especially Uldaman, just become a lot more viable, and a lot more worthwhile. I'll still probably skip a lot of this stuff as I level alts, simply because I like to solo and it slows me down to have to wait around for a group to form, but I might pop in a few dungeons instead of not doing any like I usually do.