Google Blogoscoped has noticed that Yahoo has done a small redesign of the homepage, moving the Yahoo logo back to the center, expanding and uncluttering the header in the process. Furthermore, some sections (shopping) got dropped from the homepage, so it generally looks a bit cleaner than before. You can see how the old version looked in Google Cache.
On a side note, has anyone noticed how blazing fast Yahoo's homepage is? Kudos to the coders over there for realizing that every milisecond counts when you have millions of daily visitors. The CSS as well as Javascript is embedded in the HTML; I personally wouldn't do it that way, but maybe it somehow helps with loading speeds.