Build a Better Bloglines

Sometimes Bloglines seems evil. And it does things that aren't super smart. And the social aspects of it are minimal at best. (My recommendations didn't change for months, but I add new feeds all the time. It still thinks I want to subscribe to Dilbert. It's wrong.)

All I really want is to keep track of which things I've read, across multiple machines. Bloglines is actually pretty good at that. But I don't need to use the same feed reader as thousands of other people. It would still be nice to see recommendations from friends, and a higher level view of what's going on. I'd like to see the best bits of reBlog, del.icio.us, Digg and Technorati in the next generation of online feed readers. I'd like a Flickr style privacy model, with a friends/family level, a contacts level, personal items, and a bunch of "public if you look for it" things for everyone else.

I'm imagining a feed-reading web-app for small groups (2 – 150 people?, roughly):

• It should probably behave like most of the other aggregators out there, web-based or not. Netnewswire etc. “Three-paned aggregator” seems to be standard. No reason to change that (yet, though I'm intrigued by 'River of News' metaphors). Subscriptions to RSS/Atom feeds. Subscriptions in folders (or tagged?). Optionally public/private.
• "Highlights for me" would be iTunes-style smart playlists/smart folders e.g. items less than 1 day old, items which link to things that someone else linked to in the last week, items about feeds I subscribe to, items about feeds other people subscribe to, items from my friends, etc.
• Not a "whack a mole" system. Unread items will decay, but it always shows you the latest items. Feeds archive forever for search purposes, but if you missed it, you missed it. 2389 unread items are pointless. (If you miss a whole month, use "highlights for me" to catch up).
• Behave like a good HTTP citizen. Move broken feeds to a different folder and poll less frequently. Prompt for clean-up every so often. Poll once-a-week feeds daily not hourly. (Things which require real-time notification should be email subscriptions or SMS alerts, they're not sensible RSS feeds. Things which always have status like the weather shouldn't really be here either.)

For bonus points:

• Monitor time spent reading each feed and the frequency of reading each feed (in an AJAX-y way, no doubt).
• Weight favoured feeds in "highlights".
• Show sparklines (or similar) for feed activity.
• Be smart about certain types of feed: pick out enclosures from all my feeds and give me a custom podcast URL, filter out Flickr photos or del.icio.us posts on request.

Who's building this? Is this where someone tells me Bloglines already does half of this stuff?