The Sirius|XM channel uses a completely custom drawn poster screen using the roImageCanvas. I intentionally made it look like a poster screen, but it isn't. It was a pain in the neck to do, so I wouldn't recommend it.
My Channels: http://roku.permanence.com - Twitter: @TheEndlessDev
Instant Watch Browser (NetflixIWB), Aquarium Screensaver (AQUARIUM), Clever Clocks Screensaver (CLEVERCLOCKS), iTunes Podcasts (ITPC), My Channels (MYCHANNELS)