Are date code 2010 micrcontrollers OK in 2014?
They ought to be fine.

If you are soldering with a reflow process (infra-red, hot air or wave) rather than hand soldering, then moisture absorption is a real problem, and after 4 years I would have my doubts however well they are stored.

However this has a solution, whose specific details ought to be documented by the manufacturer : they must be "baked" at an elevated temperature (in the 80C region) for a specified time (hours, possibly overnight) before board assembly, to reduce the moisture content; then soldered within a few days before moisture can build up again.