The merger isn't even approved yet, let alone done, and Comcast has already said that once it is done, current TWC customers in Ohio (and I'm guessing some other areas) will be sold off to Charter.
Updated info from DSLReports: Existing TWC customers in Ohio, Wisconsin, Indiana, Kentucky, and Alabama will become part of Charter. Current Comcast customers in Tennessee, Michigan, Minnesota, and the states above, will also become part of Charter.
They have a deal in place to show the feds that they will not have any overlapping areas after the merger, so they are not removing competitors from the market.