Screenshot/blog here: http://yokozar.org/blog/archives/225
A bug was fixed recently in Gnome that allows thumbnailers to not be 96x96 pixels. Combine this with a standard Wine icon, icoutils for extracting an exe/dll's embedded icon, and a bit of magic and you can get icons like those above.
The version numbers come from the .exe metadata. I think it's really slick, and will try and have it installed by default with Wine 1.2. At the moment it exists as thumbnailer code for Gnome, which means other desktops won't benefit, however provided they can be told to run a script to generate an icon it should be fairly easy to port.
Code is available in the gnome-exe-thumbnailer source package here: https://edge.launchpad.net/~ubuntu-wine/+archive/ppa
Please note that this is an updated version of the proof of concept gnome-exe-thumbnailer package I put in Lucid (which is ugly and uses the overly large 96x96 icons, and is thus not default and has so far gone unnoticed).
Thanks, Scott Ritchie