I have a question about the Skald - does the class get the same 'multiclass versatility' feature that the other bard gets?
He doesn't get that. They still get Song of Rest and the +1 to untrained skills, but they lose the multiclass versatility by going down the Skald path (so, the alternative would be going normal bard and swapping into skald aura via the feat).
The skald stuff is very interesting as there are a lot of interesting ways the skald bard can go. While he has the option of using his Charisma for melee basic attacks with one handed weapons, he can go Stregth for two handers, or Dex for ranged, since most of the powers refer to basic attacks and/or basic attacks with a weapon.
That's even more fun with multiclassers, since you can grab the Skald Aura and have it 'active' for an entire encounter and have it modified by power swapped dailies. If you are a half-elf, one of the at-will attacks that modify the skald aura lasts all encounter long anyway, so you don't even need to get versatile master to make use of it all encounter long. An, as far as multiclass options go, most of the powers don't have any stat requirements, with a few that give bonuses based on charisma, and some skill based stuff. So the Intelligence as a secondary stat is sort of like the Charisma as a secondary stat for the Executioner ... it's a suggestion, but there aren't any specific reasons to favour it over other stuff. For light armor users, Dex could be a better payoff, especially since most of the powers would work with rba's as much as mba's.
In all, the book is an interesting mix of old school stuff with some of the essential ideas. The bard is very much like the knight in terms of having encounter powers that modify attacks instead of being attacks themselves and having at-wills that are sort of stances that modify mba's, but the power structure follows the original AEDU structure, and can be mix and matched with the old class, etc. Really a best of both worlds approach.
The druid has a bunch of cantrip type things, in addition to the vine rope they have a pseudo mage hand + light power, something similar to prestidigitation, a detect poison thing, and an encounter power which allows for clearing some difficult terrain away. The witch's new cantrip is a nice addition to go alongside Spook and Suggestion, as it let's you use Arcana in place of a Stealth check 1/encounter (I can see some nethermancer's poaching that one).
The bard gets some neat stuff that is comparable to the wilderness knack's, that I guess would be settlement knacks. They are optional, so it's up to a DM to allow the "Sings of Influence", but they make for some interesting RP benefits. They can get themselves and their allies some special services when they get to town, either free room and board, easy access to transport, a meeting with the people in power, a few people willing to do some menial tasks on your behalf or access to someone that will provide a cheap ritual freely.
The multiclass powers are a bit stronger than older ones, as the barbarian 1/day gives all MBA's +1d8 per tier, and the skald bard one gives a heal per encounter (compared to the two feats required to do that via the shaman path).
The berserker fury mechanic is very interesting as a character's build can really determine how defendery or strikery the character is, since using a primal power instead of a martial power is one of the ways to hit the switch, so using any of the old powers (with the built in striker damage) ends your defendering, which is an ingenious solution to how to stop a barbarian from being a defender that poaches existing striker powers that doesn't go the traditional essentials route and denies access to older powers.