From jam.canoe.ca, James Earl Jones gives a few details on Anakin in Episode 3 (while some of the news below has been reported, it still contains spoilers):

... As for Star Wars, he really is coming full circle as Vader. Plans are to return him as the voice of Vader in part three of the new Star Wars trilogy, which currently has a release date of 2005. "George Lucas says 'When Anakin goes bionic -- (highlight to read) that will be in the last five minutes of episode three -- they will hear you." (end spoiler).

He gives his seal of approval to Hayden Christensen, the current Anakin Skywalker and the man who will be Vader. "Aren't you impressed with him?" he says. "I like his whole bearing, the spine, the neck ... he's like a snake."

Not that he feels at all proprietary about who plays Darth. "No," he laughs, "the little kid (The Phantom Menace's Jake Lloyd) got me over that."

For more on Jones' life and career, hit the link above. Thanks to Ice Drummer and Grilled Sarlacc for the heads up.