The HathiTrust now has a live 0.2 beta version of its impending books and journals bibliographic search. They currently have records for around 4.5 million titles, including 708,118 in the public domain (inc. the Internet Archive books and journals, which they have ingested). A breakdown of the holdings by academic discipline is here. Some of the blurb underneath the beta’s search box seems to come from May 2009, and is out-of-date.