The DS has always been a fascinating platform for me and ever since I got it 4 years ago (went for a black Lite when they came out) it's impressed me time and again. Developers seem to be more inventive and prepared to take risks with DS titles; partially because of the lower budget required to produce a DS title (generally) and it's more limited capabilities. I'm sick to the back teeth of the constant high budget, flashy, cut-scene heavy, gameplay lacking titles on pretty much every other platform. The DS to me has been a great source of varied and interesting gaming, if not always incredible, certainly different.
Here's hoping that the 3DS can continue in this pioneering vision that the DS has established.