Over on Zeldman's blog, a post with a heartbreaking title.
At first, Twitter looked like it was going to be a friend of the open web, possibly because it was started by people who came from our world. Or possibly because that was good marketing. No matter, the people who run the show at Twitter today have no love the free-for-all that is he web. The one that allowed writers, geeks and designers to work together on wonderful collaborations called blogs.
To Zeldman, I left a comment that hopefully puts it in perspective.
The same fate you've left to RSS applies equally to your beloved CSS. Your CSS skills will go the way of COBOL programming if Twitter and Facebook replace the web. If you don't want that to happen, support technologies that preserve choice. Like RSS.