This would definitely be a feature I would like to have integrated in Dexpot.
Actually I´m using DM2 http://dm2.sourceforge.net/
for just having this functionality.
Meaning: extra bloat for the 99% of the DM2 features that I don´t need, extra icon in the tray, etc.
Also DM2 is the only program besides miniMIZE that I know of that has this functionality.
Unfortunately it appears that both programs have not been updated to Windows versions beyond XP
The possibility to minimize to an icon that floats on top of everything is invaluable when you have little desktop space (that´s why we all like Dexpot, right?) and need to be able to have a quick look at another window without having to pop up a task-bar or tab through a list of running programs.
A real life example: You are drawing a 3D model in [your favorite 3D program here] after a reference photograph. Being able to pop up [your favorite image viewer] for a quick peek without slowing down the work-flow is priceless.
Yeah I know, multi-monitor setups are just for that. But......I don´t do that stuff for a living and so it does not justify the extra monitor (yet).