An article from the DVD & Blu-Ray Review magazine, Issue september 2011, confirms that Matthew Wood has put his voice in the audio tracks of all 6 movies:
http://www.mediafire.com/?jqi7gcgvzqvcbd9
[page 35 of the magazine, page 6 of the pdf]
The magazine scan is from projektstarwars.de, posted by Spaceball:
http://www.projektstarwars.de/forum/rund-um-star-wars/50693-star-wars-blu-ray-disc-40.html#post1399176
Interesting to read if you ask me...