I remember the earlier Google attempt at the same thing. I was in undergrad and an engineer came to my Uni to give a presentation on the topic. A big area of concern was "Why won't Google just shut this down when the going gets rough?" The question was mostly batted away along the lines of "this is lunch money to Google anyway." But just a couple years later, it did indeed bite the dust.

Covered in Wired: http://www.wired.com/2008/01/google-to-provi/

Update: And the shutdown article, 11 months later: http://www.wired.com/2008/12/googlescienceda/