If you login to your AdSense account you will have to pass through an "Accept Contract" page which has updates to the AdSense TOS; "revisions to this agreement in the following sections: 1-7, 9, 15-17."
One of the largest features added for the publisher, are two new payment methods. (1) Secured Express Delivery: Secured Express Delivery ensures that your check arrives quickly and safely by using a courier service to send your check to you. (2) Electronic Funds Transfer (BETA): With Electronic Funds Transfer (EFT), your payment is deposited directly into your bank account in your local currency.
The second largest addition added to AdSense yesterday was a new ad format named Ad Links. They look similar to those text links one would buy to increase one's link popularity and rankings on a site (but these won't do that). For more information on Ad Links click here. A note, you can now have 3 normal ads plus one ad link ad, making a total of 4 google adsense ads on a page.
It is also important to read Jensense's thoughts on the changes, she is the authority on Google AdSense, so of course you would expect GoogleGuy to stop by.
Now let's move to the forums:
DigitalPoint's forum has three threads on this update; one about Ad Links, an other about having 4 ads on a page, and the final thread is on the topic of the new payment options.
SEO Chat forums has two threads on the topic, the first on new payment options and the second on overall adsense changes.
Cre8asite Forums has a thread discussing the new ad link format.
WebmasterWorld has two threads on the topic (1) Google Ad Links and (2) New Payment Options.
Discussion also at V7 forums, IHelpYou and SEO Guy forums.