It has taken us almost 4 years to get all but 8 production databases off of SQL2000 to 2008R2. Yes, we still have 8 on SQL2000! We have also been upgrading some SQL2005 to 2008 as well. With about 325 production databases I know of very few that are purchased apps that have certified SQL2012. Heck, in January we just installed a new system that we FORCED the vendor to certify Win2008R2/SQL2008R2. They are still running Win2003/SQL2005 in their hosted site and have over 20,000 prod dbs.

We haven't even looked at Win2012 or SQL2012. We are too busy with current and coming projects right now.