On my desktop, I have the icons zommed in a bit. The icon for Mumble that is used now has a low resolution and doesn't look very well when zoomed in.
So, I added 256x256 and a couple of other resolutions to the file icons_mumble.ico which is located here: http://mumble.git.sourceforge.net/git/gitweb.cgi?p=mumble/mumble;a=tree;f=icons;hb=HEAD
I think this have been a thing that many users have been waiting for. :)