Over the long term, I don't think products like Tivo have a future, for two reasons. First is more philosophical: If you can get any content you want on demand (like some kind of video program) via broadband, you don't need a device to store it. Second is more practical: If you do need something to store it, I think a "media computer" with a Tivo-like software program will be cheaper and easier to use, and will not require that you give away all your personal information (what you watch and when you watch it), like Tivo requires now.
Having said all that, the Yahoo!-Tivo partnership makes sense in the short term (next 3-4 years) because we have very limited broadband connections, and so what will become popular is downloading IP video programs overnight, storing them on your Tivo-like device (or your media computer), and watching them later.
This partnership creates, in effect, a new distribution channel that short circuits the traditional Hollywood system--competition, in other words, which is always a good thing. And it may sell a few Tivos as well, which is a major concern for Tivo, since they can read the writing on the wall too. They need to sell as many Tivos as they can over the next several years, before the devices become obsolete.