The new TechNet Wiki has not made it public (although it’s still considered beta).
Among the Wiki pages, we of course have the Exchange Wiki. Not much there yet, but hey if you have something to share then go do it.
Find the TechNet Wiki here and the Exchange specific section here.
Cheers,
Henrik Walther
Technology Architect/Writer
MCM: Exchange 2007 | MVP: Exchange Architecture
MCITP: EMA + EA | MCSE: M + S | TechNet Influent