For me it is important - especially as a consultant I need to stay on top of new technologies - but it is not everything.
I'm not going to take a pay reduction just because I could work with SQL 2014 (there is not that much new for BI anyway :-)).
I would be dissapointed though if I could not work with at least SQL 2008R2.
(I would already be frustrated if I had to miss those windowing functions from SQL 2012, to be honest)