>>you can click on it and get a definition of the word.<<
Here's a twist... The link takes you to the dictionary.com definition, and you're also given a link below the definition to the "10 most popular sites for [this term]," and clicking that takes you to... Ask Jeeves, where you get ten partner site results, followed by 10 Direct Hit results, and accompanied by one or two pop-ups.
thats one heck of a journey, quite surprising google has let it go
Not really surprising to me. Google isn't Microsoft; they don't think they have to control everything their partners do. They're also not afraid of competition from other search providers; they still occasionally link to the competition in the footers of SERPs, remember?
But while we're on the subject, has it occurred to anybody else that Google Glossary is a test for replacing dictionary.com ?