I think for a lot of DBAs it's a comfort thing as well.

I know I have all my tools set up the way I like them, all my alerts fire properly when they're supposed to and my monitoring stuff gives me a good picture of what's happening, and what happened a while ago.

When problems with the apps happen, I know exactly where too look to hit the problem quickly.

I *still* get confused by the 2008 activity monitor change 🙂 when I have to use the 2008 SSMS and yes, it's going to be a huge investment in time and resources to upgrade to 2008 and then 2012 and still provide the day-to-day support of the existing infrastructure.