Happens all the time.
Oddpost (email provider) was just bought by Yahoo! The second the ink was dry on the signatures sealing the deal, Oddpost stopped accepting new accounts.
http://www.oddpost.com/learnmore
Something similar happened when Microsoft bought Visio.
Similarly, www.picasa.com now redirects you to
www.picasa.com/google ever since Google bought it 
MS probably recognized they were going to need some kind of improved search capability in Outlook (à la
X1) before Longhorn
Not sure why it would be under MSN, except to say that an
MS employee was recently arrested for allegedly stealing search engine source code from his former employer, AltaVista. Maybe they need to re-write some stuff. tee hee hee
