Gotta admit that this is pretty lame of them.
To be honest any high-volume news portal / ugc site that doesn't support RSS is quite purposeless.
For those look for Dribbble feed replacements, check out https://dribbble.hittter.com
So things like muzli won't work anymore?
This, to me, is the worst thing they could come up with. Don't know the reason behind it, don't know what their problem was with that feed.. But I do know there's no more dribbble for me. I hardly ever go straight to their site and check the popular section. Normally I would've received about 300 pieces a day, at least 30 of which made me click and got me on the actual website. That's done now.