Google continues to end projects, the most recent one being AdWords for Print. The blog post that explains the decision shows the big picture at Google:
"In the last few months, we've been taking a long, hard look at all the things we are doing to ensure we are investing our resources in the projects that will have the biggest impact for our users and partners. While we hoped that Print Ads would create a new revenue stream for newspapers and produce more relevant advertising for consumers, the product has not created the impact that we — or our partners — wanted. (...) As we grow, it is important that we focus on products that can benefit the most people and solve the most important problems. By moving resources away from projects that aren't having the impact we want, we can refocus our efforts on those that will delight millions of users."
That's the reason why Google closes or stops investing in small projects that couldn't attract a big audience. Google Answers, Google Notebook, Browser Sync, Lively, Hello weren't very popular and Google decided to close them. Some of them were open sourced and migrated to Google App Engine, while others became start-ups. This is a big opportunity for start-ups: create services that aren't likely to go mainstream in the near future.