Let me step back and explain what is happening, so you really understand it.
What is changing is that the advertiser will not see the full referrer data, including the keyword string, passed through to their server. In short, when someone goes to Google, searches for widget and then clicks on your ad, Google would communicate the details of that click through what is called a referer. Now, a lot of what is communicated in that click has been removed, including the keyword the person searched for. That won't pass to your log files, through the referrer data or to the standard analytics packages.
Does that mean you are losing the knowledge of what people are searching for to click on your ads? Nope. Not really.
The AdWords reports still show them to you, the APIs still give them to you and a lot of the AdWords software built by third parties use the API and thus nothing has changed with those applications. But, the raw referer data is gone and just like with organic search, that data won't be passed through the referer and to your log files or analytics.
What is interesting is that there are ways to get the data but not necessarily the true keyword data. You can use ValueTrack, a parameter you can set in AdWords to trigger the destination URL to include the keyword and other parameters. So technically, you can set the destination URL to have that data, such as:
The keyword parameter will pass for the specific keyword that triggered your ad. So if you aren't using that, you can. Of course, again, most of tools automatically handle a lot of this.
This impacts mostly those who don't use those tools or who relied on basic Google Analytics and/or old fashion technology.
You can learn more about this over here.
Forum discussion at WebmasterWorld.