I would sooooo have been in on this if only I knew about it! In the old version, though, I noticed there wasn't a lot of correlation between gallery activity and forum activity, so if something was announced just on the forums, odds are it wouldn't reach a lot of people. With integration of the forums into the main page, though, I think that'll change now in v.4.
I'm still seeing that same disconnect between the main site and the oekaki, incidentally. I feel like they're two separate sites; they don't even look much the same, and there's not a lot of overlap between the oekaki community and the site at large (most oekaki artists don't post much to their galleries, and most heavy gallery-posters don't oekaki). To run slightly off-topic, any way we could integrate the oekaki more into the rest of the site? At least make it skinned the same, and maybe allow an option to auto-post a finished oekaki drawing to one's gallery?
ahem anyway...
I like this idea. ^^ Better yet, let the users create the categories / group themes, so we don't run the risk of having groups that are so large as to be pointless (e.g. an Anthro Art group or an Anime Style group would contain, oh, everybody on the site; but a Fox Furries group or a Haruhi Fanart group would be a little more useful).
I think this is the best idea proposed so far to increase commenting; of course, people will comment on what they're interested in. Other than that, just don't be so shy, guys! Rifle through the Recent Uploads and speak your mind about something you notice in any of the pictures. No matter what you say (as long as it's tasteful, of course), the artist will appreciate it, so don't worry about your comments being "useless" or "wrong." ^^
Also, I think being able to award more than one medal per day for one-star accounts would encourage more one-star account holders (which is most people) to comment more. At least I get the feeling that I don't want to use up my one daily medal because I might see something later that I'll wish I had saved it for, so I'll hesitate to comment at all.
I'm... not sure how I feel about having artists as wishlist items. There are a few really great and prolific artists on here, and I can just see that either they get so swamped with wishes that they never have time for their own work, or that they gain a reputation as that jerk who never answers commissions. I think it'd be a little better to have styles, themes, and subject matter as things to put on your wishlist, then contact artists individually if you want them to do something for you. I had the thought of a "Preferred Artist" trait to add to wishlist items, but that seems like it would discourage other artists from offering to take up the task.
Anyway, those are my thoughts. ^^;