V13 Highlights
-  New geotargeting options: Target multiple geographic levels (countries, regions, metro areas, and cities) within a single campaign, target specific regions of multiple countries in a single campaign, and setup negative targeting for specific regions (for example, target the United States with the exception of Alaska).
- New reports: Generate Search Query Performance and Geographic Performance reports using ReportService and DefinedReportJob.
- Mobile image ads: Use the new MobileImageAd ad type to create graphical advertisements for the mobile content network.
-          Suggested campaign budgets: Retrieve budget suggestions for your campaigns withgetRecommendedBudgetList.
- Active campaigns and ad groups: Want to retrieve only your active campaigns and ad groups? Now you can, using getActiveAdWordsCampaignsandgetActiveAdGroups.
- Quality-based bid and Quality Score support: We've added two new Keywordfields:
- firstPageCpc(first page bid estimate)
- qualityScore(Quality Score of the keyword)
    Per our versioning policy, v12 will be supported for four months from today, after which time it will be turned off. Therefore, please make sure that you upgrade to v13 before February 20th, 2009. As with every new version of the AdWords API, we strongly encourage you to review the Release Notes section of the Developer's Guide to learn more about this version.