Sorry to say, Yahoo's days are numbered.
The search engine's inferior to Google's, MSN Messenger outclasses it and signing up for e-mail can be nothing short of nightmarish, at times (for some reason, it always re-directs to the main page after signing up for a free account, which means you'll have to sign up all over AGAIN.)
Don't be surprised if MSN Yahoo! becomes a reality. When it all comes to down it, it's really Microsoft vs. Google: Who Eats Who First?