Slave1.jp is reporting that a 1/2 scale Darth Vader will be released in July in Japan for the price of 64,000 Yen ($570US or $695CDN). Unfortunately, I'm not sure who will be releasing it. The following information is translated from Slave1.jp:
"The reservation of big size DarthVader of 1/2 scales was started. The breath sound of Vader is done the internal organs, the gimmick where the light/write saver radiates with single three electric battery 3. Total length: Approximately 1m, manufacturer details obscurity. Sale day: 2005 July reservation price: 64,000 "
(ignore the attached pic - it's the same as above)