Group Policy can do a lot but it can't do everything. For example, there's no policy setting you can configure that will disable wireless functionality on mobile computers even when they're disconnected from the company network.
If there's something you'd like Group Policy to do that it currently can't do, Microsoft provides you with a way of submitting your request. Just go to www.WindowsServerFeedback.com and tell them your suggestion. Please publicize this link with other admins you know who work with Windows Server systems, as the more the enterprise IT community makes its voice known, the more likely Microsoft is to hear what they are saying.