We have 2 x SQL2000 servers and 5 x SQL2008R2 servers. I have an ongoing project to migrate all databases to our new servers (SQL2008R2), but I do it inbetween other projects and that spare time seems to get less and less. We still have about 40% of our databases on SQL2000. Our mix of in-house applications to third party applications is about 70% to 30% and 90% of the third party applications were migrated to SQL2008R2, maybe because it's easier, less integration. 😉