Mark Coker of Smashwords blogs about it here. He takes a guess at how much Scribd will cut, and it's pretty mind-boggling:
Effective immediately, I estimate 80-90 percent of Smashwords romance and erotica titles will be dropped by Scribd, including nearly all of our most popular romance titles. Books priced at free are safe and will remain in their catalog.
Based on what I've been able to glean, the lower the price and the higher the word count, the better the odds the book will remain. Few books priced $3.99 and above will remain. Scribd is not publicly revealing the formulas for what stays and what goes, probably because much of this is still in flux. They're cutting all publishers and distributors with the same blunt knife.
If he's right, they're basically nuking the whole genre.
Now, this doesn't affect me, obviously, because I don't write romance. I checked my Scribd links on the sidebar, and they still work. (For now. *fingers crossed*) But it's still a seismic event in the self-publishing world. And it definitely sucks for readers who will no longer have access to the stuff they want to read and for the writers who were supplying them with it.
Maybe Scribd will figure out a way to make their business model work. I really hope they do. The self-publishing world is better off with more retailers, not fewer, and I'd hate to see Scribd fail.