In-House Counsel - Limited License to Practice Law

In an article at Law.Com, the current trend to require limited licensing of In-House counsel is discussed. This would mean in some instances that an attorney would be required to be licensed in the state wherein she works as in-house counsel, and in some cases she would have to register or get limited licenses in all of the states that the client company operates. Apparently NJ is charging $750 each, for such a license/registration. This can get really expensive, really quickly. And why is it necessary? Is it more than a fund raiser?