Google has launched a new page in the AdWords help center that helps advertisers keep track of what has changed, feature-wise, with the AdWords platform. The new page can be found over here.
It contains the data and description of the change, plus, when available, a link to more information either in their help center or on their blogs.
Google said over 200 products and feature updates launched in AdWords last year, and it is hard for advertisers to stay on top of all those changes. This page is designed to help with that.
Forum discussion at Google AdWords Help & Google+.