I agree with others that this is a nice list of the new features but not Best Practices.

I would not advise to reset Compatibility Level because your current version of your application may use features that are not supported on 2005. The exaple is an industry leader CRM application ( I don't want to name names) where I ran an Upgrade Advisor.

For the Best Practices I would start with ones for developers and ones for sysadmins. Updrades are fine, but what about the new installations? I am still waiting for the best practices for placing features on the drives for 2005. In 2000 I would put Program Files on the OS /Program Files RAID 1 and Data Files on RAID 5. In 2005 when you install, the Data Files feature is a subfeature of Database Engine feature. And I would not put feature and its subfeature on separate drives. This is just an example of what could be a best practice advice.