I think the Brand Extension was a great idea and should stay the way it is. You have to look at it from all sides and all sides point to great idea. If the WWE were to go back to one brand, the Smackdown Main Event scene would become WWEs Mid Card scene and the ECW Main Event scene would become WWEs Lower Card scene and forget about the current Lower Card scene on any show, let alone the Blue and Black Mid Card scene. They would still have the three shows, but if you recall, Raw and Smackdown, pre Brand Extension, was just 4 hours of the same $#!+. What you saw on Raw is what you saw on Smackdown. I think financially, entertainment-wise, and any other aspect of business, keeping them separated is whats best for the company. More, in this case, is better. More shows, more time, more Stars, more Titles, more money!!
Then again, a unified WWE vs. TNA could be nice. Imagine a main event scene with HHH, Orton, Batista, Cena, Big Show, Edge, Jeff Hardy, CM Punk, Chris Jericho and Rey Mysterio vs. Kurt Angle, Samoa Joe, Jeff Jarrett, Sting, A. J. Styles, Mick Foley, Christopher Daniels, Booker T., Kevin Nash, and Scott Steiner. I really have to stop day dreaming.