Toward the issue of using mobile devices as a way into corporate networks, this article about a new trojan targeted for Symbian smart phones is exactly the kind of thing I'm talking about. The trojan is named MetalGear and disables anti virus software when run. While this particular piece of malware does not seem focused on gathering privledged information, it is the kind of thing that could.
http://www.pcworld.com/news/article/0,aid,119035,00.asp