Google is planning to update Google Maps API version 2 on 25 March.

There are two major changes:

• API Console keys will be supported, including Geocoding and Directions.
  See here to obtain a key: Tutorial install/use and Google Maps Usage and Billing
• All invalid keys will be rejected.

Another reminder that the V2 Maps API is deprecated, and its deprecation period is coming to a close. Please upgrade your maps to the V3 API.