MCP Magazine Online released a feature earlier this week titled Storage Strategies for a New Exchange. Much of the article shows that the storage calculations for Exchange 2007 haven't changed too much from 2003. E2007 still runs, after all, on the great-when-works-but-thoroughly-frustrating-when-broken Jet database engine.

One interesting piece I didn't know has to do with changes to Exchange indexing in E2007:

In an Exchange 2003 environment, I usually advised people not to use content indexing because it consumed a tremendous amount of system resources. In fact, the index itself was 35 to 45 percent of the total size of the database. In Exchange Server 2007 though, the index has been completely redesigned and only adds about five percent to the size of the database that is being indexed.

Check out the article at: http://mcpmag.com/features/article.asp?EditorialsID=697