I have to admit that I fell in love with Enterprise Search... Finding stuff within an Enterprise is a very challenging task that differs in many ways from searching html or pdf on the web. Some of the questions I started to ask myself were:
If your interesting in these topics, my paper on "Architect and Develop Search-Enabled Enterprise Applications" might be an interesting reading for you ;-)
BTW, this will also be the topic for my TechEd.session in Barcelona.