Both the Release Candidate (RC) for Exchange 2010 and the Service Pack 2 for Microsoft Exchange 2007 were just released, and if you're at all considering migrating to Exchange 2010, get both of them now. Exchange 2007 SP2 lets you install the release candidate for Exchange 2010 within the same environment as Exchange 2007, so you can have the two versions of Exchange coexist for better testing and transitioning.

And the Exchange 2010 RC allows an in-place upgrade to the forthcoming RTM version, so you can use this co-existence strategy to smooth your eventual migration to Exchange 2010. In fact, that's the best way to migrate, as you cannot perform an in-place upgrade from Exchange 2007 to Exchange 2010; instead, you have to move your mailboxes and such over.

[ The InfoWorld Test Center evaluates the Exchange 2010 beta. | To learn more about Exchange 2007 SP2, read J. Peter Bruzzese's column "What Exchange 2007 SP2 brings to the table." ]

A final installation note: You do need to have Windows Server 2008 to run the Exchange 2010 RC.

And why bother with Exchange 2010? In previous blogs, I've outlined what's new. But two capabilities I'm excited about are worth repeating here:

■New high-availability functionality: After working with CCR and Cluster Services in Exchange 2007, it's a joy in Exchange 2010 to move to Database Availability Groups (DAG) that use failover clustering features without actually having to configure a cluster. (Note that you have to be working with the Enterprise version of Server 2008 to see this feature in action.) I took the time last week to set this up myself, and it was so much easier than the high-availability tools in Exchange 2007: Just configure the DAG and create the database replicas -- you're all set. Scott Schnoll, a principal technical writer at Microsoft's Exchange team, has posted a few videos on the process.
■Voicemail preview: Aren't voicemails annoying? We are just so impatient these days (at least I am), and voicemails demand time to listen to before you can figure out if they're worth the listen. Well, the Unified Messaging role in Exchange 2010 can take the voicemail and transcribe it to text (speech-to-text) so that you see the transcribed version. Is it 100 percent accurate? No, but accents and quirks in the way we speak make that impossible. From what I've seen, it's pretty close.
In addition to the RC being released, the Exchange team has provided a host of complementary tools worth investigating. They include the following: