This could be a good or bad thing. Supposedly, MyNetworkTV currently can be viewed in roughly 109 million homes whereas SyFy only receives 97 million. However, ratings are always higher for Smackdown seeing as how it's the secondary brand for the WWE and not just an offshoot like ECW and NXT. Higher ratings for Smackdown means people would be more likely to watch NXT, coming across the same channel and whatnot, but then you also have to take into account that without MyNetworkTV's commercials running for the WWE, it may hurt them. Having a presence on three different channels spreads out your marketing rather wide and MNTV is a network station. I don't know too many people that don't primarily use their cable television but there are still people out there that may not even have cable (especially in this economy).
I firmly maintain my previous idea that I feel it's best if the WWE would figure out a deal with NBC to have Smackdown move to Saturday night ON NBC itself. If Saturday is such a bad night for TV that they don't like putting new shows on, why not put something there that has a built-in and loyal fan base? Guaranteed, Smackdown would pull in better ratings than reruns or some of the other shitty shows Saturday nights entail.
Will there be a new look, a new theme, and all the others that go along with the move? I doubt it. They just shifted things around for the MyNetworkTV. It'll be interesting to see how this effects the upcoming 2010 Draft on April 26th. Last time around, they moved some big names over to Smackdown in fear that without it, people wouldn't migrate to the new channel. I can wholeheartedly see that happening this time, quite possibly with Randy Orton or Triple H being the big face that moves over.