Comcast's proposed merger with NBC could require the combined entity to offer video to others online, according to sources speaking out Monday. The FCC's proposed rules for the telecom giant would prevent it from withholding content from any competitor, including Apple's iTunes, Netflix, Vudu or other digital services. Agency officials might also require a net neutrality rule that prevents it from interfering with traffic from these or any other legal service, the WSJ's insiders said.