It's an interesting experiment. Especially if, as we've been hearing, it represents thinking that's going in to a new version of My Yahoo. I can't see what this site offers over the current My Yahoo, aside from the capability to add custom search engines. However, adding a search engine that's not already supported on the service is hugely difficult. Compare it to adding a custom search to the Google toolbar in your browser: you just right-click in the search window on whatever site you're on and select, "Generate custom search."
Still, as an experiment in custom search, it shows realistic thinking. Even major search engines such as Google and Yahoo don't do the best possible job with results from other structured services, such as Flickr. Yahoo has got to make it easier to add your own search, but perhaps that's the reason the company is running this experiment, for now, on the other side of the planet.