I'm writing it as a single-user (for myself only) project. Is there enough interest out there for me to put it up as a project? (That's only a little extra work; I'd just need to add logins and user accounts.)

I really miss delicious, and none of the others that I've tried are any good.

Also, my RSS reader has one neat feature. On WordPress and Blogger, there's an undocumented feature that lets you grab older items (?paged= on WP, ?start-index= on Blogger). That's really useful when you find a new site and want to look at the history.