IMO using TNG era antagonists in an OS reboot would be a waste. There are many, many TOS threads left to pick up and weave together so why not save the Borg for TNG reboot?
I also wouldn't go with Khan again so soon
. Over the course of the next few films, let the events of ID slowly stir up the best of the regular OS species to the point of all out WAR then
unleash Khan forcing them all to work together against a common foe. [/fanwank]