I've become a big fan of the recently released BrushBox, which lets me put bush and tool presets in the same folders, and makes it simple to define those presets. It does not give a stroke preview, so we don't see the affects of pen pressure, but we do have a thumbnail, and we can control the size of the thumbnails from the slider third in from the left at the bottom of the panel. It's not perfect yet. A folder created inside BrushBox can not easily be saved, closed, and reopened, but they are working to respond to user requests.

Incidentally, seeing you are a fan of Kyle Webster's brushes, Kyle has written a nice testimonial for BrushBox
BrushBox - A better preset manager for Adobe Photoshop
http://derrickb.net/brushbox/BrushBox%20FAQ.pdf