Remember all of this talk about big media companies making their own YouTube? Well word got out today from Broadcasting&Cable that Viacom, owners of MTV, Nickelodeon and other big channels has backed out of the talks with NBC Universal, News Corp. and CBS. It looks like the big guys simply can’t agree on anything for their own good. Until Tuesday afternoon, Viacom was a big part of the talks. Why they backed out is unknown at this point, although it could be due to the fact Viacom’s MTV Networks Online and News Corp.’s MySpace are direct rivals to each other.