Am I being overly optomistic or are you saying that you have done work towards implementing the freedesktop.org Icon Theme specification and that we can choose from different themes? (because that would be phenomonal).
I don't know about the freedesktop.org Icon Theme specification, but the patch allows dia to use .png icons for the complete toolbox. Everybody who's able to create 24x24 pixel .pngs
will be able to create his own dia "theme". Steffen