Apparently we have not made this clear enough yet, so I wanted to say it explicitly:
Everybody should get the choice to receive HTML or plain text
If you personally prefer text-only email, you should always be able to set your email client to show plain text, and all your newsletters should a have plain text alternative for you to read. We totally agree! The Email Standards Project is trying to improve the rendering of the HTML portion of the email, not to get rid of the text portion, so there is no need to worry.