This is the day (Wednesday) that Rupert Murdoch's News Corp divides in two -- one, to retain the News Corp name, will include the company's troubled newspaper and publishing companies; the other, to be called 21st Century Fox, will include the company's entertainment assets, including the 20th Century Fox movie studio, the Fox broadcast network, the FX cable network and Fox News. Although both companies will have Nasdaq listings (as FOXA/FOX and NWSA/NWS), trading will not begin until July 1. Most analysts have strongly endorsed the split, But MBIA analyst Richard Greenfield has expressed doubt about it, downgrading his rating for the company to neutral from buy. We will look to reassess the opportunities in both FOXA/FOX and new NWSA/NWS shares as we get a sense of where each is trading relative to our initial viewpoint on the valuation for each, Greenfield said.