This is already done for free with more options with MortButtons. All the features and more (skinning etc). I assign a different MortButton menue to each of the Wisbar buttons. This is a great set up. Selecting the icons is a little clunky because you can only brouse through one icon at a time. Another option is to use ShortcutCreator (
http://forum.xda-developers.com/viewtopic.php?t=60823) then use Mortbuttons.
http://www.sto-helit.de/modules/edito/content.php?id=42