Nice recommendation!

The book description sounds a lot like data mining. Isn't it? Why didn't they use the buzzword anywhere?

It does some data mining, but there's also a lot of soft AI (optimizing an airline travel search, building a basic search engine).

It's quite good, although there are a number of annoying typos in the code, a trend that I've noticed recently with a number of O'reilly books unfortunately.

Still, definitely worth a read, the intro to practical applications of some of the AI topics in particular is really cool.

Partially it seems they're jumping on the Web 2.0 crowdsourcing long tail here-comes-everybody bandwagon; partially because by focusing specifically on 'collective intelligence' they're actually narrower than data mining per se. But primarily I think the former, to give the book wide appeal (and lots of sales!).