On the plus side Wizards recently rehired Monte Cooke (lead designer of 3rd edition) and have announced he will be the lead designer of the revamped game. I like his work and I'd like to think that with Cooke back at the helm 5th edition could be a positive move for the game. But I guess I'm a cynic at heart and right now I despair at the thought of having to buy the core rulebooks yet again.
Its early days and development has not even got started yet. I guess release will likely be sometime next year but a lot will depend on financial and business pressures to get the new game published.