In WMP 12, there is an option called "Play to" which you select and can then choose which device you want the media to be played on.
I would like to use a Surface tablet to control media from and have it play on my TV, by just using it as I would normally. I.e. I dont want to have to right click each and every time, then select play to, and then select my WDTV. Would be nice to have the command of Play to, to be the default action.