I've bit the bullet on all development servers (did it on about 10 servers last week). It's been running fine on all but one server. I couldn't get it successfully installed on one of my dev servers. I have an open case with Microsoft on this one.
If you are using Backup Exec on your servers, you might want to modify the permissions on the master$4DIR, model$4DIR, and any other $4DIR file you see in your DATA directory where the .LDF and .MDF files reside.
That will fix your SP2 issue if it refuses to install.