you’ll notice on some art there is a “xxx Comments on CGTalk” link - so at the moment we’re just hooking into CGTalk for the comment system, this is however only for images that have been submitted into the CGTalk gallery and been accepted.
As it stands, we have several types of comments in portfolio - blogs, guest books, and gallery posts, there isn’t a lot of uniformity to them, or the way they work. One of my side projects is to build a uniform way to maintain posts, so that every post can have it’s own comments thread. This would mean that all images would have comments built into them, and you could comment on blog entries, or even comment on comments. It should offer a lot more flexibility.
I’ve also been thinking of building some easy hotlinking into the bbcode - so that you can easily link to other people’s artwork and portfolios within posts.