Will there be a literal millennium? Yes, I believe so. When the promises were given to the patriarches, they understood them to have an earthly fulfillment. Too many people do not see the fulfillments so to make God look good (as if God needs to be defended) they "spiritualize" the promises away. Indeed, there is a spiritual component, but all the promises have physical, earthly counterparts and must not be forgotten.
What was promised? Many descendants, They would populate the 4 corners of the Earth. They would become a great nation and a multitude of nations. They would be blessed and be a blessing to all. They would possess the gates of their enemies. Certainly not a shabby people or a weak Jewish nation that needs help according to these definitions. In addition, there was to be a lineage of Kings, and the throne over Israel was realized in King David with an eternal covenant. That throne, although it is the Lord's, is an earthly throne and not in heaven as some would have us fancifully (and without scriptural support) believe. Yet, the bible makes it clear that Jesus will be given that throne (and does not possess it yet). IN order to do so, there has to be a literal reign here on this earth. It must be so in accordance with the promises otherwise God is a liar.
Those who would spiritualize the millennium have no grasp on Israelite theology and expectations (but rather some Gentile interpretation of it), and dismiss probably close to 90% of the bible in favor of some abstract replacement--- they do not really understand what the bible teaches at all.