The DS and the two kinds of save.
Tomorrow in Japan Nintendo starts a nationwide test of its Nintendo DS "download service." (Read: demos) via kiosks in certain stores. DS users will be able to download game demos and additional content. The game demos will remain on the DS until it is turned off... BUT...
...the additional saved content such as original scores in the game Band Brothers will remain saved on the memory card for play any time. Stellar. A classy move on Nintendo's part and hopefully an indicator of the (rumored) online service to announced (rumored) in as little as 4 days.