This year, you won't have to wait until August for the latest ''Lord of the Rings'' DVD. New Line announced that the ''Return of the King'' DVD will be out on May 25. (With no installment due in theaters in December, there was no need to delay the release to whet fans' appetites for the theatrical release of the next chapter.) The record-tying 11-Oscar picture will be released in a two-disc set that includes the 3-hour, 20-minute theatrical cut of the film and a disc of such extras as trailers and TV spots. Alas, you'll have to wait until the end of the year for the special edition set, which will contain Peter Jackson's four-hours-plus director's cut. Further down the road, a boxed set of all three films, running more than 11 hours, is probably inevitable. By the way, we'd like to thank everyone in New Zealand for making these DVDs possible.