This via the Google Geo Dev Blog (http://googlegeodevelopers.blogspot.com) as the company announces to nix the Maps Data API after Jan 31, 2011. Recall that as of several months agao, Google Maps API v3 renders data stored in Fusion Tables, a Google Research project for storing large structured data sets in the cloud as a result, Google has decided to recommend Fusion Tables as our cloud storage solution of choice for geospatial data going forward, and to deprecate the Maps Data API.

According to Google, The Maps Data API will continue to be accessible until January 31st 2011, and Maps created using the Maps Data API will remain accessible in Google My Maps beyond this date " See details HERE