The Maps Data API expires today.
http://googlegeodevelopers.blogspot.com/2010/11/maps-data-api-deprecation-announcement.html
Version 2 of the Javascript Maps API expires on May 19, 2013.
http://googlegeodevelopers.blogspot.com/2010/05/they-grow-up-so-fast.html
It's a good idea to update Version 2 maps to use Version 3, but they
should continue to work for a bit longer. As long as you don't use the
Data API; it doesn't look like you do.