The Tenth Amendment has no application here, whatsoever. This is a merger between two companies that participate in interstate commerce- which always has been and most likely always will be, regulated by federal rules created by Congress. "We, the people" has as much standing as you going into a ballot box to cast your vote for your member from the House of Representatives and your state's Senators. "We, the people" is a widely used paradigm that the Founding Fathers had no real affection for, as the direct election of Senators by the people wasn't even around until the 20th century during the Progressive movement. Your only recourse as "We, the People" was the direct election of your House representative, which is the less powerful of the two legislative bodies. So your recourse is to vote for someone else as your House representative, and they MAY decide to vote against the appointments of the President to agencies like the FCC or the Justice Department. I love when "We, the people" is used so ineloquently as it completely corrupts the original intentions of the Founding Fathers. Again, if you have a problem with it, take it up with Thomas Jefferson.
In this case, neither company is a monopoly. Comcast may be the only cable provider in your area, but I assume you live in the US and are able to receive DBS from DirecTV or Dish Network, free OTA television from FCC licensed stations, or television through the internet through a variety of sources- cable again, DSL, dial up, etc. NBC also has no monopoly, as its distribution still mainly lies in its local affiliates, which are licensed through the FCC.
