Just read the LWN article about Ximians Desktop2 http://lwn.net/Articles/34940/
You can learn that they install proprietary software like a pdf and a flash plug-in with their redcarpet service.
Most disturbing is that they changed the standard save format for Openoffice to be a propietory format, not helping http://www.gnu.org/philosophy/no-word-attachments.html at all. This is even bad for the companies that desktop is targetted at and we should get the word out to this companies that using proprietary data format is really dangerous for them.