Matt Vernhout just posted this message on his excellent blog:

Announced today the MAAWG Senders Best Practices Document (Version 2.0 - pfd) has been officially released.

Updates to the documentation include:

• New guidelines for legitimate email avoid being mistaken for image-based junk mail.
• List permission and opt-in recommendations have been amended to reflect current best practices.
• User-unsubscribe processes have been clarified.

along with a number of other updates to the document.

This is a great document to read as a marketer, and should set the bar for your marketing programs.

And in response to @covati's question on Twitter @EmailKarma added: that recommendations changed "enough that you should review it.  But maybe not enough to have a drastic impact to your process".