What's Jerry Yang gonna do to revitalize a slumping Yahoo? Andrew Goodman has a very good list of action items for Yahoo!
The biggest thing I'd suggest is: "Be the Next Facebook".
Yahoo has all the pieces to build a next-gen homepage portal, and they should copy most of Facebook.
Facebook's weaknesses are:
That's it. Those are really the same things. It's not clear how useful Facebook is in organizing your life if you are not mainly into hooking up with hotties. And Facebook is run by a bunch of 24yr-olds who are trying to figure out how to make it more appealing. That's a limitation.
Yahoo already has the platform. They have, what, about 10X more profiles than Facebook. Yahoo has properties like Yahoo! Groups which are incredibly useful for soccer-moms. Yahoo is good at APIs. They have the Flickr braintrust.
Also, Yahoo already shows MUCH BETTER ads than Facebook does. And they do have a great ad salesforce.
Yahoo needs to re-invent My Yahoo, copying the best of Facebook's social features (like friends 'confirming' where they met you), opening the the social graph, integrating useful features like Groups, Flickr, Finance, Answers, Sports, etc.
They need to copy some of the design minimalism that Facebook is good at. They don't need to keep adding slow-loading graphics everywhere - like they've done with sports.yahoo.com - ruining the experience for someone who just wants to check the damn scores.
Anyways, I think Yahoo has the kernel of this idea already. Semel talked about it endlessly.
To do this, MASSIVE FOCUS is needed. That's what Facebook has that Yahoo does not! Either Jerry Yang turns the battleship around fast (like BillG did back in '95), or he'll watch Mark Zuckerberg take over Yahoo's last bastion of hope.