Mydaho - 3:15 am on Jun 26, 2010 (gmt 0)
Answering my own question. I sent a message to Yahoo and got this reply (excerpted):
"At this time the Search alliance only pertains to Yahoo! Search and not the Directory. The Yahoo! Directory will remain a human-created and maintained collection of websites organized into categories and subcategories. Yahoo! editors review these sites for potential inclusion in the Directory, and to evaluate the best place to list them.
The Yahoo! and Microsoft Search Alliance includes search (Web, image and video), search advertising and contextual advertising. After the transition, Microsoft will be the provider of Web, video and image results to Yahoo!, and the basic list of results provided will be the same as those displayed on Microsoft's Bing engine. Yahoo! will continue to enhance the search results page as we do today to make the overall experience of finding stuff online and getting things done easier for you."