Filed under: Portable AudioIn a move that could finally sound the death knoll for the universally-hated digital leech known as DRM, Sony BMG Music will reportedly become the last of the top four major labels to offer unprotected tracks for download. Citing people familiar with the arrangement, BusinessWeek.com reports that full details of the label's plan will be released "in the coming weeks," although at least part of its catalog will supposedly be available without DRM sometime this quarter. If this does indeed pan out, Sony would follow EMI,