On the Nintendo’s side of the industry the try before you buy set up is pretty much non-existant minus renting games or downloading the rare addition of DS demo downloads on the Nintendo Channel. Iwata confirmed that Nintendo will be bringing demos for select WiiWare titles to at least Japan. Iwata said he had doubts that demo promotions are the way to go though.
There is currently no time frame on which these demos will become available.
Thanks Easytutorials and evandeck