The WDTV Live SMP does have a video wall built into the firmware, but the older version does not unless you run the B-Rad user written firmware.
AFAIK (ie I've never owned or even used a WDTV Live) the video wall is not easily customisable to change the way it looks & behaves, and IIRC you can't use it with streamed media unless you create the cover art via a PC.
For the Dune players there are at least half a dozen different media wall programs you can use to get it looking as you want it. The only real downside once it has been created is that the Dunbe wont load it automatically on startup - you need to navigate to the video wall and manually run it each time. However Dune will hopefully be adding a video wall to the firmware at some point in the not too distant future.