No, the best way to handle it for WotC would be supporting 4e with few new things, and supporting a new 5th edition or a something more "retro" which bases of 4e but with a more modular system.
Wizards would be fools, if they decide to pull the plug and actually stop supporting the online tools.
As long as 4e is supported, they actually should do a 5e ASAP.
Not an edition that should please everyone, but an edition that allows for a different kind of playstyles... and I would not try to bring back the pathfinder crowd. People who want something more similar to ADnD are a much better target IMHO.
I am sure there are a lot of people playing pathfinder and 4e who would instantly switch if such a system will exist. (Or even better: no need to switch, as your DDI account allows you to get material for both games.)
Nearly all of those articles my Mike Mearls in the las 8 month were fantastic. He had great ideas, pointed out problems, pointed out how problems in the system were overcome by roleplaying.
Give me an edition based on d20 that incorporates those design principles, and I would actually play it.
Just to make sure: feat and talents need to be different design spaces, as someone said in a different thread, I would however like them to be called combat and non-combat proficiencies!
@WotC only wanting to sell books: they need to do that, and the best way to do it is creating the best D&D experience ever, and if that means two parallel editions side by side, so be it.