Bloglines, acquired by Ask Jeeves roughly a fortnight before it was itself acquired by IAC, is doing some interesting stuff. It recently introduced a package tracking capability and it intends to add weather, stocks and other personalized information (via RSS feeds). It already has news.
Watch it morph into a MyYahoo!-like application. If thoughtfully integrated with Jeeves' search (and by extension the rest of the IAC network), it could be the sticky anchor (how's that for a mixed metaphor?) for the entire system.
I think that MyYahoo! is the model for personalization for the masses and Bloglines could emulate that functionality and ease of use. Plus the blogging component offers the potential to develop considerable user-generated content (a la Yahoo! 360).
So rather than Jeeves being the front door, Bloglines could be an alternate way into the content, search results, verticals and ads in the IAC portfolio. We'll see.