It'd definitely be nice to have some Mysidia themes with matching MyBB forum themes (since MyBBis the easiest to hook up with Mysidia).
(Also, there's more that can be done with themes than there currently is. It'd require some other modifications, but you can also display a user's username/currency/unread messages, etc. in a toolbar or something.
I wrote a tutorial on it but few people see it since its not really a mod nor a theme by itself. I think people would appreciate stuff like this being incorporated into themes. <3)