There is a TON of information in the new Iwata Asks series on the DSi.  I skimmed through some of it and noticed a couple cool points about the system that I thought were interesting:

Iwata: Okay, thanks everyone. You haven’t left anything out, have you?
Mita: Um, this isn’t really something to bring up last, but the Nintendo DSi has a reset function. The reset button also serves as the power button, but when you press it, it doesn’t just reset. With Nintendo DSi software you can move around, return to the menu, or play a different game, without shutting down the power every time. As a game console, I feel like it has a strong sense of unity. It’s very subtle, but I hope everyone experiences that.

Iwata: Speaking of subtle aspects of the Nintendo DSi, I like the way when you insert a game card that game’s icon pops up on the menu, and when you take it out, the icon disappears. Before, when you changed games, you had to shut off the power once. With the Nintendo DSi, you just lightly press the power button to return to the menu, and change software without turning off the power.

Read the rest of the interview here