VC1 not a supported codec. While some legacy boxes may still be able to play it, the vast majority of the Roku players in the field (from the introduction of the Roku2) do not have any support for VC1.
Hoping that Roku 4 will support VC-1. Is perhaps a licensing issue at play here? Unable to play back the video portion of marquee BD remuxed titles including Casino, Inception, The Dark Knight, et al. Please do not advise me to transcode the video (I authored parts of ffmpeg and mplayer on the the Arch Wiki so I know what can be done) as that would utterly defeat the intent of a BD remux. Besides, many of the earlier Warner VC-1 encodes are already bit-starved and any further transcoding would be senseless.