We reported earlier that Google AdWords is sunsetting the AdWords API version 12 on February 23, 2009. Google has been forced to extend that deadline to March 9th, due to the Perl library not being updated until recently.
The Perl library is managed by a third-party, outside of Google and it just took him extra time (of his free time) to get this done. So, Google decided to push off the deadline to March 9th, to give people a chance to update their applications. The Perl library is now updated and can be read about at this thread.
Jeff Posnick of the Google AdWords API Team warns that version 14 will "contain numerous fundamental changes. All of the client libraries will need significant updates to support the next release." So be prepared.
Forum discussion at Google Groups.