Am I giving Pligg a plug? I guess so! 🙂
Pligg (blog) is an opensource contender to what we're doing – in terms of having built in user feedback. Take a look at all the pligg-like site. Here is an article "To pligg or not to pligg". I like the way they have tabbed the "tags/options/comments" – that another great way to hide complexity until you actually need it.
On the topic of opensource. Opensource will always duplicate the really popular software (DIGG is quite popular!) and that's a bummer for a company employing people who have spent bunches of money building something. Opensource eventually moves software from "for sale" across into "for free". Microsoft did it to Netscape ("you can't beat free" Gates crowed as he bundled IE with Windows and Netscape crashed and burned). I bet Gates regrets saying that now, because he was right… you can't beat free. Sigh.
But it's how things are these days. Our only response can be to use the revenue we earn from reBlogger to build better and better things, to stay out in front.