IBM's new Ubuntu-based desktop offering

There is a inherent tension between promoting FOSS and promoting proprietary software if your support for Free software is principled rather than just on a case by case basis. FSF has demonstrated that conflict repeatedly but there are other efforts as well.

Benjamin Mako Hill did a presentation which offers the perspective that pointing out flaws in day to day life with using proprietary software may be a better tactics than just pointing out advantages of using Free software

http://mako.cc/copyrighteous/20080808-00

The website http://revealingerrors.com/ from him is very interesting. You might consider that negative marketing and perhaps it is but I wouldn't be dismissive of the effectiveness of this strategy.