To follow up, as I had to run earlier; I would say that there is nothing wrong with saying a certain song was "given" by God, since every good gift does come from Him.
But it would be similar to the man who stood up in our church 2 years ago and said he believed God wanted us to rebuild a church in Haiti that was destroyed in the earthquake. I believe that idea was from God, and we did end up doing exactly that...now, that man is not infallible, and anything anyone says should be tested for both consistency with scriptures and for general wisdom. I have no problem saying God "inspired" that man to say that, as long as we realize we are speaking of something different than the inspiration of scriptures.
The same could be said for "It is Well", or "In Christ Alone," or "Jesus Freak." In each of those cases, we could say the song was a gift of God, but that it was though of, and written down by a flawed human, and so none of those songs are as good as they might be had God written them perfectly himself. And any song, old or new, COULD have some error in it, and so all music considered for church use should be examined for doctrinal truth.