From the Law Librarian Blog on a one and a half hour interview with Google engineer Anurag Acharya on the Law Librarian Blog Talk Radio looking into Google Scholar Legal Opinions and Journals:

Google designed this for people who know how to use Google at the very least, and to be successful with mining cases with that level of experience. No one will see something like a citator beyond the “How cited” tab. The panel clearly hungered for a more definitive free tool that matches Shepards or KeyCite. Don’t expect anything like that soon, if at all. Acharya pointed out some technical difficulties in doing some of the things Lexis and Westlaw does for a case opinion database. Google is not going there. He also alluded at one point to agreements he has in place that prevent him from doing certain things, such as creating an API to embed case information in third party sites. This suggests that whoever is vending the text [Westlaw?] see the raw case law as a commodity. The real value to a vendor is the analytical tools they provide. The contract essentially seems to be that someone provides the text at a reasonable price provided Google does not compete on features.

Further comment on 3 Geeks and a Law Blog.

Update: comment on HeinOnline Blog.