5 years 'maybe'. Lots of money going into it, but still a ways to go. Don't think they even have color yet do they? Think how long LCDs have been out and are only now begining to achieve widespread performance / affordability levels. And once they get OLED tech right they have to agree on standards, divvy it up between the investors and get yields etc worked out. Meanwhile exisiting technologies find new improvements and new ways to reduce cost. Remember just a few short years ago optical drives were going to wipe conventional hard drives off the planet? The cost of a MB of disk storage fell like a rock and optical never got a look-in.
Don't hold your breath.