Amit Zinman has posted an aptly named article "Overview of E12 Features" which has some information about e12s new features.
http://www.msexchange.org/tutorials/Overview-E12-Features.html
He does erronously mention that Exchange's Jet database is used for WINS and DHCP, however if I recall correctly those products use Jet Red (aka the Access version of Jet) whereas Exchange uses Jet Blue which share the same database theory aren't the same technology.
- Joel