Tivo announced their Guru Recommendations program yesterday, allowing editors of popular magazines to share suggested show listings. It sounds like a good program, as finding new shows to watch is generally the most difficult thing to do with a TiVo (esp. if you're avoiding channel surfing). I'm sure the magazines pay for placement slots, but I would be interested in suggested shows from Entertainment Weekly and Automobile.
Of course it'd be way cooler if any TiVo user could create suggestions and share them on the TiVo site, like the way Amazon does Listmania. It wouldn't be too tough to extend existing TiVo Online accounts and the online scheduling, along with some browsing and voting by TiVo users to filter the best recommendations to the top.