Really liked the article Is Google Badly Designed? on Google Blogoscoped. He talks about the design considerations with Yahoo and Google and their home pages.
I thought it was interesting that Google was viewed as "friendly" because of its simplicity. Clearly Yahoo puts a lot of information on its page but it also feels very corporate.
From what I read, Google is having trouble getting people to use its other features. It'd be interesting to know what to degree this is because they're not displayed the way that Yahoo's are ...