Us too. Until very recently many of our system were on 2005 and most others on 2008R2. I do a lot of testing concepts on my personal laptop to be ready for writing and now that we have actually started using 2012 for OLTP stuff and 2014 for our data warehouse. Of course, it can be pretty hard to have to use old versions of SQL Server once you have gotten even somewhat proficient with the new features.