Here's some fairly important ones:

The northern state of Uttaranchal in India was officially renamed Uttarakhand on January 1, 2007. This has not yet been reflected in any of the Google Maps which seems to reflect a big oversight or an oddly long lag period between updates. The same goes with Pondicherry which was renamed Puducherry in September 2006!

The marker for its provisional capital of Dehradun is also erroneous and ends up some field to the southeast of the city. It should be: lat=30.33357, lon=78.04776