When you read the blog post used by the Exchange development group to announce the forthcoming Microsoft Exchange Server 2010 SP1, you'd be forgiven if you thought that the version now available wasn't fully baked when Microsoft released it in November 2009. To be blunt, SP1 is a huge upgrade for Exchange 2010 because it completes many of the most compelling and interesting features introduced in the RTM version.

Take Role Based Access Control (RBAC), for instance. RBAC is at the heart of the Exchange 2010 authorization model, and it's a fundamental concept for administrators to understand as they approach a deployment. However, the Exchange Management Console (EMC) doesn't let you manage RBAC components such as roles, role groups, and role assignments. Instead, you have to use the Exchange Control Panel (ECP), only to find that ECP offers limited ability to create new roles and manage role groups and assignments. Therefore, you're forced to use Exchange Management Shell (EMS) cmdlets if you want to do any real work with RBAC. SP1 changes the picture completely by providing an enhanced UI that makes RBAC much more approachable and easier to manage.

Retention tags and policies are another example of a vastly improved feature. Exchange 2010 RTM forces you to do all the work to create new retention tags and policies through EMS, which is OK as long as you're used to EMS and can figure out what has to be done with the various cmdlets that you have to use. But then you see the new UI exposed in EMC by SP1, and you realize that creating and implementing retention policies is now a matter of running a couple of wizards. What currently takes hours to do should take only minutes with Exchange 2010 SP1.

Microsoft has also learned from experience and user feedback. Discovery searches are a good example. These searches work well in Exchange 2010 RTM, and it's easy to create a search that scans every mailbox in an organization for evidence of wrongdoing. However, such a search might return tens of gigabytes of items to the discovery mailbox, where search results are stored. SP1 improves matters by letting administrators perform an estimated search first to discover how many items will be uncovered if a full search is executed. You can then tune the search criteria to find more or fewer items, as desired. And you can deduplicate search results by telling Exchange to copy only a single instance of a discovered item rather than the duplicates that might be stored in multiple mailboxes. These are small but important tweaks that make life easier for those who have to interpret search results and respond to legal subpoenas.

Lots of attention will focus on personal archives and the news that with SP1 you can place a personal archive in a separate database from its primary mailbox. This change is good because it creates a lot more flexibility for administrators; you can group archives into specific databases that might run on low-cost storage or even use specific servers that do nothing but host archives. Upgrading Outlook 2007 to be able to access personal archives is a no-brainer decision that removes a huge deployment blocker for many organizations that simply aren't interested in deploying Outlook 2010 until they've had a chance to test the new software thoroughly and prepare users for its deployment. Microsoft hasn't given any details yet about how it will provide the upgrade for Outlook 2007, but I expect to see it released as an update for Outlook 2007 SP2 or even incorporated into the next service pack for Outlook 2007.

I also like the news that SP1 includes new cmdlets to let administrators import data into a mailbox from a PST without having to install Outlook onto an Exchange server. This situation makes it much easier to convince users to move from PSTs, which are invisible from an administrative perspective, to using online personal archives—which are searchable, indexed, and manageable. Cmdlets will also be available to export mailbox data to PSTs.

On the client side, the changes made to Outlook Web App (OWA) make what was an attractive client better performing and better looking. Some features that should have been in the initial release (calendar printing!) are now included, and the availability of customizable themes lets users express a little more control over their web-based client. My personal favorite is the "herding cats" theme.

All in all, there's much in Exchange 2010 SP1 that recommends it for early deployment after Microsoft releases the code later this year. It's just a pity that the features that SP1 brings to the table weren't available in the RTM version of Exchange 2010.