The problem is this quote from the article:
The unit would reportedly monitor media such as weblogs and would also employ "surrogates", or top politicians or lobbyists who could be interviewed on TV and radio shows.
Yes, the Pentagon should have a PR department. No, it shouldn't be paying politicians to promote their point of view.
All that does is undermine their reliability. If this starts happening, anyone who speaks (or posts) in favor of the administration's policy or viewpoint will immediately come under suspicion of being on their payroll.
US interests are always better served by honesty and transparency in government. To put it into a sound bite: the moment dishonesty becomes policy, all policy becomes suspected of dishonesty.