The 70-236 is not like other mcse exams (or should i say "older server 2003 exams").
There is a slight change - M$ are going for high end servers.
This means a very complicated system of "server roles" (hub transport, edge transport, mailbox, client access), an effort to be more "linux like" with a heavy emphasis on server command line usage, and a lot more complicated ways to use clustering.
Oh, and it's still using ntbackup.
For the exam, ignore most of the practice test that M$ ships, it doesn't relate to the actual exam questions very well. Even more, ignore using the software (or simulators) because there aren't any simulations!
Public folders are officially deprecated (aka not included in the GUI), but you'll need to memorize all of the Powershell commands on how to setup, replicated, restore, and give permissions for them.
DO memorize every possible command line parameter. (event-log, get-user, get-mailbox, get-mailboxstatistics,
DO memorize every variation of "Server Roles" and configuring those roles.
DO memorize configuring their "new" technologies: Outlook webaccess (webready Documents & Sharepoint permissions), Outlook Anywhere,
DO memorize every possible permutation of Exchange & clustering (from setup to disaster recovery) - because this is obviously what most server deployments use. (Linux cluster?)
edge server subscription
hub transport setup
setting up client access