I hate it when I read threads of Google AdWords API users who found out too late that the API they have integrated their software with no longer works and that they either lose money or time due to not having the right data (or any data) sent back from the API. This is why Google and blogs like this, give you guys fair notice that you should start coding and testing the new AdWords API with your software.
The new beta AdWords API v2009 is out and now finally available to all advertisers. This was announced a couple months ago but was a very limited beta, now it is open to all to use. It is a major upgrade from version 13, so expect major changes between the two.
So begin reading up on this new API at code.google.com/apis/adwords/v2009/ today.
Forum discussion at AdWords API Help.