By integrating your AdSense account with a new or existing Analytics account, you値l have access to in-depth reports about user activity on your site. In addition to the wealth of metrics already available in Analytics such as unique visitors and visitor language, you'll now have access to granular reports that break down AdSense performance both by page and by referring site. Armed with this new data about user behavior, you値l be able to make more informed decisions on how to improve the user experience on your site and optimize your AdSense units to increase your revenue potential.
From: Make a date with data in Google Analytics
The integration is like an advanced AdSense report cross-referenced or cross-segmented with the various metrics GA provides.
Thus, you could have a look at which pages generated the most income and where the people who clicked on those ads live, etc.
(I can hear some script developer's revenue crashing...)
I really like the potential of this idea. Not that extra data with Adsense always helps, I find. Sometimes it's of the type "so John bought a winning ticket on Sunday ... soooo..."
Can't wait to see this enabled on my account!