Our upgrade policy tends to be driven by Micorsoft's support cycle rather than new features.

(ie It is relatively easy to get money for an upgrade if we say the old system will no longer be supported.)

We managed to get rid of our last two SQL2005 instances last year when Windows 2003 went out support.

The bulk of our instances are now SQL2008R2 although we do have one SQL2012 production instance.

We might get a production SQL2014 instance this year but we will start moving our DBs off SQL2008R2 next year to give ourselves time before Windows 2008R2 and SQL2008R2 go out of support.

I suspect most of our DBs will end up in SQL2016.