I don't believe anyone is thinking broad enough. Using features provided in many modern mobile devices, I believe an attacker if driven, could compromise a mobile host(smartphones/tablet), and use it to do a variety of things like pivot, rouge-AP, remote bluetooth/wifi spectrum analysis... You could probably do a lot of remote exploitation through the 3g connection, and micro SD cards can hold 2tb(theoretically) so, its really a matter of who, when, what, and where.
If you are an enterprise or any business that needs a more secure data policy then I suggest having a "check-in" for all devices before entering a specified structure or area.
Trust me when I say mobile devices are not being looked @ heavy enough in corporate security. The same with any wireless devices such as personal cameras with wireless eye-fi chips or any personal wireless router.
PAN/BAN networks are a real threat as they can get as close to the target as possible with the least amount of resistance. How do you think stuxnet was deployed? (a flash-drive)
Hope it helps ;-0