So, with all the wasted space over to my left (and the left of other posters too), I finally got around to thinking of this one.
The avatar maximum resolution was 80x80. To make people happy, I've upped it to 100x100. So have fun photoshopping new avatars to take advantage of the extra 3600 pixels that you can now use, photoshop kids!
File size is still capped at 25KB for that. If anyone's seriously running into that cap, let me know. In my testing, most jpegs were coming out in the 4-6K range per image, so 25 is pretty big on the overhead I think, but I'm not an insane photoshopper like some of you are .