Change Data Capture (CDC) is a very nice feature that I think will be very popular among DBAs grappling with ETL (Extract, Transformation, and Load) processes. CDC allows SQL Server to capture which rows and columns have changed on the defined columns and put the changes into a separate table that can be queried by ETL. The benefit is knowing -- without having to perform extensive queries -- which rows have been inserted, deleted, or updated. Currently, finding these operations in a table isn't easy, and you quite often have to write code into your process to mark these activities. But with CDC, you can define these audit policies at the database level and not have to make those drastic changes to your application code.
 
This release also brings Policy-Based Management (PBM), which is a way to define policies for any number of boxes that will be either enforced or alerted on when the server is out of policy. You can define almost anything for your policies, so even something like making sure that no tables begin with the prefix "tbl" would be one policy that you could enforce. You can make another policy that says all databases should be backed up every day, in order to be alerted if one of your servers misses a backup. PBM is going to be a very powerful tool for SQL Server going forward, and so far, I really like what I see.

Jewels of Katmai
There are far too many new features in Katmai to discuss in one place. I didn't even get a chance to touch the almost complete rewrite of SQL Server Reporting Services or all the work that was done in SQL Server Integration Services or SQL Server Analysis Services. And then there's the management data warehouse, interactive Dundas drill-down reports, IntelliSense, the new activity monitor, PowerShell integration, and much more.

For most SQL Server shops, I think the big news in this release is going to be data compression and the CDC, because both are going to affect shops where it counts: their budgets. The Resource Governor is a nice feature, but I think it's still too young and has too many limitations to make the splash Microsoft is hoping for. It will likely take another couple of releases before Microsoft turns it into something that can make a real difference in a lot of shops.

Compressed and filtered indexes are going to make a difference right away, and while caveats exist with filtered indexes, if you use them right, you'll see the benefits you expect. The tools have also seen some significant improvements, but there will still be disappointments for DBAs who don't want to be treated like developers. But as long as it took to release SQL Server 2005, this version is shaping up to be what SQL Server 2005 should have been from the beginning.