If it's actually comprehensive, this is a very big deal. I don't know how LexisNexis Westlaw are going survive now that Google is giving away a huge chunk of their services.
(Of course, this stuff has always been technically in the public domain; and much has even been online in disparate and badly organized sources.)
1 - Lexis/West both allow lawyers to search based on jurisidiction. If I am a lawyer in Florida, then I want to see results from Florida front and center. A decision from a state court in Arkansas is not directly relevant. It might be interesting, but I don't have time to sort through 50 state courts just to find the one Florida case that affects my client.
2 - Lexis/West both have access to the "official" versions of opinions. Many courts release opinions subject to a lot of technical revisions (fixing typos, changing citations, etc). The opinion is considered final only after all the technical revisions are complete. Many online sources do not reflect the technical revisions. I don't know where Google is getting its data, but lawyers (who value certainty and hate risk) would be willing to pay $5 to Lexis/West to make sure they have the absolute most final version of a case.
3 - Lexis/West have PDF versions that show the proper pagination/column-ation of the cases as they appear in print. This seems silly, but when you are in court talking about a case to a judge, you need to make sure that you can say "I win because of what the case says about halfway down the right column on page 451" and have the judge open his copy of the book and find the statement in the right column of page 451. Eventually, judges will move to line-numbered books and this will be irrelevant. But in the meantime, lawyers want to have the identical version as the judge.
4 - Both Lexis and Westlaw employ people who summarize and categorize the cases. Keyword search doesn't work if the court does not use your keyword. If a case is about landlord/tenant law, the Lexis/West will categorize it and tag it as "landlord/tenant" (as well as a LOT of other things) even if the words "landord" and "tenant" never appear (maybe the opinion calls them "renter" and "rentee").
I don't think they will. I interviewed with them and there was a general atmosphere of desperation, suggestions of needing to work weekends and hollidays. I mentioned Google to them and how Google will eventually want to get access to _public_ court records, and it seems like that question made them really uncomfortable.
Well, they enjoyed their (virtual?) monopoly for so many years, now Google gets to enjoy theirs.
Mead-Data (Lexis) came in during the 1970s with its Wang-style dedicated workstations and its newly formed databases and had a huge disruptive effect by offering the first system of electronically retrievable legal authorities ever. The system was very clunky when I used it in law school in the 1976-78 era but has since been highly refined and is highly useful for those willing and able to pay the high price associated with the service.
Lexis eventually undercut the West monopoly and sent West scrambling for a competitive response (hence, Westlaw).
The competition between Lexis and Westlaw did lead to far better pricing for some users, from the old "x dollars per minute" model to flat-rate pricing for users in specific categories (e.g., small firms), but this still involved hundreds of dollars per month at minimum (anything beyond the specific categories remained x dollar per minute).
Of late, other services have cropped up (LawNet) that have made a lot of the case law available at much cheaper fixed pricing (e.g., under $100/mo) but their offerings were incomplete.
The trend is unmistakable. For Lexis and Westlaw to compete, they will eventually have to lower their pricing considerably. Even then, there is a serious question whether their resultant margins will leave them with a viable business model. Only time will tell on this.
By the way, the downward trend for Lexis/Westlaw is tied to the vast disruption that has occurred with Big Law, which, in its heyday, was a massive user of such services that paid little attention to the cost aspect (costs were simply passed on to clients). In our cost-conscious era, Big Law is reeling in the short term, as are Lexis and Westlaw.
http://wiki.answers.com/Q/What_is_the_difference_between_hol...
West certainly provided added value in the beginning, but that kind of service needs relentless quality control of a kind that West hasn't served up for a long time.