It would seem that they are. Their president and CEO, Howard Stringer, gave an interview this month. This segment caught my eye.
“Apple’s iTunes Store uses its own proprietary DRM called FairPlay. I think this gives Sony a chance to provide something that Apple can’t. And we have to move ahead and grab that opportunity before Apple begins to provide support for other hardware and blocks us out.”
http://techon.nikkeibp.co.jp/article/HONSHI/20090427/169423/?P=2