You probably already know about the Yahoo! 360 beta. I have started playing around with it after Jeremy Wright was kind enough to send me an invite a while ago. As you can see from the blog that it isn’t anything too fancy and your customisation options are pretty limited. You can’t, for example, edit the template of the page very much and things like AdSense ads are pretty much out of the question (I don’t see Yahoo! hosting a competitor’s ads).
On the other hand, if you use Yahoo! for other stuff then 360 is pretty handy because it draws most of those services together into one very convenient interface. That is its purpose after all. If you would like to give it a try, why don’t you drop me a mail and I’ll send one your way.