''Lord of the Rings'' fans awaiting the now-traditional late-fall release of the extended version DVD of the latest ''Rings'' movie will have to wait a little longer this year. Trade publication Video Business reports that New Line won't be releasing the ''Return of the King'' special edition DVD until December. In the past, the director's-cut versions of the movies had been released in mid-November, allowing plenty of time for holiday gift shoppers. New Line sources tell Video Business that the shorter window this year won't matter -- there's already a high enough advance awareness of the lengthy disc (which, with 49 new minutes of footage, means ''ROTK'' will run more than four hours), and besides, the theatrical cut, released two weeks ago, is already the year's top-selling home video. Why the delay, then? Apparently, it took longer than usual to gather all the principals to record commentary tracks, the cast having long since dispersed to other projects. Guess it's hard to keep the hobbits down on the farm after they've seen Minas Tirith.