It is a nice concept, let the computer do all the work for you. Let the computer find the information you want so you don't have to search for yourself. Sounds nice, but i see a huge problem with it.
Fiirst off, i find most of the websites i like by accident. I look for something specific, and accidently run into something related that is more interesting. But if you let the computer do all the looking for you then you will be missing out on a lot. It might be convenient at times but then what about the people with small sites who still need to get there names out there. Will they have the knowledge to program their website to be compatible with SPARQL? Not to mention, everyone doing websites will have to learn yet another technology that many customers will not be able to afford but will want anyway.