Google has released a lot of new services that live inside other Google applications, without having a standalone interface. It's an interesting approach that facilitates the adoption of a new service, but makes it difficult to find a new service.
Google Tasks is available inside Gmail, Google Calendar, as an iGoogle gadget and as a mobile app, but there's no standalone desktop interface. Google Buzz integrates with Gmail, Google Maps, but you won't find a separate desktop interface.
Google Social Search and Google Real-time Search are two filters in the "search options" sidebar, but they don't have homepages like Google Blog Search or even Google Patent Search.
Maybe Google decided that it's a better idea to offer new features for the existing Google services, instead of releasing disparate services.