I like your thoughts on point 1 a lot. I agree with you 100% that images next to usernames would suck very badly, because it would clutter everything up way too much. My thinking is that the image would be invisible unless you hover over someone's username for a second (the delay is so it doesn't pop up when you're scrolling through an article), at which point a 90x90 (or whatever size) image would be displayed on hover. EDIT: Another alternative to having the hover-images might be just this part: and have it display basically only what's in the left column of the profile page, which can already include images.Also, if clicking on a user's name led first to a popup similar to the markup popup, rather than directly to that user's profile page, I'd be a lot more likely to click their name to learn about them, since I wouldn't have to leave the comment page.
It could be anything though, I think that's what could be interesting about it. A form of expression more than a "hey this is what I look like." For example, my profile image clearly says, I like Hubski and I drink too much
It would be cool if the image along with some stats populated. mk has been really in to the spark-line graphs of late, that could be cool. We used to have profiles that popped up a while back, right mk? Might be cool to have a little popup teaser where you could see a bit of info as well as a "follow" button.