Engadget has some advice for TiVo (Advice to TiVo: get your software onto PCs):

So here’s some free advice for TiVo: create a version of your software that works on a regular PC and then either license it to manufacturers so they can put it on their PCs instead of Microsoft’s Media Center operating system or sell it directly to consumers so they can install it themselves (or do both).

That would be thinking outside the box and creating consumer value. So, I don't really expect a major company funded by the broadcasters to actually try it. Instead, TiVo will probably follow the blindered future noted by MediaPost (Life After TiVo, Experts Debate The Next Generation Of Broadband Enabled DVRs):

The benefit of the broadband connection [to the DVR] is that it can enable real-time lead generation, couch commerce, instant polling (without a cell phone), long- and short-form branded content, and any manner of viral Web promotions.