I just got the book today... I'll need some time to look through it, but it has a LOT of options for wizards. There are some optional rules that are different than the core stuff (such as wizard origins, which are pretty much like backgrounds, but it gives you a suggested list of powers/feats/etc like a build), and of course a bunch of wizard spells. Just from a quick glance, there's a lot of interesting powers, including some with the Weapon keyword (which use Int for attack and usually Int for dam - though i saw one that used Str for dam). There's also a couple of new cantrips.
There's a bunch of paragon paths (pyro- and cryomancers, chronomancers, and gloom necromancers to name a few), though no epic destinies that I see.
Bunch of new implements, including 4 new types of them (dragonmasks, hats, shields, and mirrors).
Here's the basic abilities of the 4 new implements (in addition to whatever magical effects the thing might have):
Dragonmask: 1/enc - extra elemental damage on an attack, or gain resistance
Hat: 1/enc - extend range of spell
Shield: 1/enc - force foe to reroll melee attk
Mirror: 1/enc - shift & gain concealment
Also, there's a new type of magic item with its' own item slot: the rune. You can have 2 runes tattooed on your body at a time (one on each arm). They have various abilities; they seem to either improve powers of a certain type or grant bonuses to skills. Though, two really stand out to me: one (a level 18 one) has a daily power that lets you regain a spent encounter power as a minor action; another (lvl 23) has a daily power that lets you regain a daily power. I haven't exactly pored over every magic item in the AV or PHB, but those two runes seem pretty damn good to me.
There's a few other things in the book, but that's all i've really looked at so far... There's also a TON of feats, and a chapter on wizard towers (not sure if they give any bonus to a character or not).
