Fear not, my friends. It appears that our report last Monday about Yahoo! Overture being dead was a bit premature. According to WebmasterWorld members, the Yahoo! Overture Keyword Tool is back. The optimistic hopefuls have revived the useful tool from the dead.
Here's a search I performed just a few minutes ago.
Contrast that with the screenshot I created last week:
It definitely looks like it's working, and it's using data from January 2007. Other forum members report that it's showing May data. I suppose it may vary per search term but I'm unable to get May data.
Forum discussion continues at WebmasterWorld.