I just noticed that the 2009 edition of the Enterprise Search Sourcebook is now available. Published by Information Today, it’s a nice way to survey the landscape. Of course, it goes without saying that you to take vendor claims with a grain of salt, but you have to start somewhere!
Of course, if you’re interested in learning more about enterprise search, be sure to check out the program for the SIGIR 2009 Industry Track–particularly the two panels: one comprised of leading industry analysts, and the other of senior technologists from the top three enterprise search vendors. Yes, I’m biased: I’m organizing it.