http://www.tgdaily.com/2006/08/31/20th_century-fox_releases_blu-ray_14_november/
There's also evidence that 20th waited for the first full-scale Blu-ray Java (BD-J) development systems to be built, enabling the studio to create richer, more interactive titles than those currently released by other studios. And while some early Blu-ray adopters voiced disappointment that picture quality was not what it could be, even compared to the lower-capacity HD DVD disc, 20th's strategy may offer a solution: By waiting for full-scale BD-J, 20th now promises titles that use full MPEG-4 compression with DTS HD Lossless Master audio. Sony's first titles, by comparison, stick with the older MPEG-2 format, which doesn't compress as tightly. As a result, some say, MPEG-2 videos play back with lesser bit rates, not taking full advantage of BD's higher capacity.