DVD players will still sell until the price of the Blu-Ray players comes down to around £100. DVD's themselves will be around for years to come. Don't expect Blu-Ray to replace DVD's in a year or so. DVD's will still be selling strong at least five years from now cos Blu-Ray equipment and HDTV is still too expensive.
Eventually all TV's sold will be HD and standard TV's will be defunct. When that day comes then all the digital channels will broadcast in high definition and TV will be a glorious place. I reckon it could take 5-10 years for this to happen. Oh and we'll all be using hoverboards to get to work. Well thats my prediction for the future.