They do, but at this point it's becoming comical, especially if they are trying to move away from search as a profit center. You need equity in people's heads if you want to conquer the market.
If instead of Google search they made 3 products each called "Google Search", "Super Search" and "YaGoo!", they wouldn't be where they're at today.
Well, they do have a lot to spread. But yeah, intense amount of overlap.