(Vivienne Gucwa)Usually by this point in the review process of a mega-merger like the one pending between Comcast and Time Warner Cable, there are discussions about things the parties are willing to do or give up in order to make the deal more palatable to critics. But because Comcast and TWC proactively offered to spin off some 3 million customers, and because Comcast already made a bunch of promises and concessions when it acquired NBC back in 2010, there hasn’t been much chatter.