I only had ten minutes while I flipped through it in Books-A-Million.
The Rotvine Defiler is a lvl 26 Solo something. A giant plant undead thing.
I really want to sit down with the Spirit-Eater Vampire (not sure) and the Vampire Muse (Elite 10 Controller). The Corpse Eater Vampire, however, looks real dull. Also, the Oni Spirit Taker looks cool (one of the Oni are not undead).
The Spirit Ooze is neat. If it hits with a basic attack, it gains phasing until the end of its next turn. While it has phasing, it gains a minor action shift, and gains a bonus to AC (and I believe Ref). It splits in half (like an Ochre Jelly), and does 2d6 with Combat Advantage.
Reapers are agents of Vecna.
Lots of mummies.