Yep, there's a port of Descent for the DS called DScent. It's been a while since I installed it, but I believe you need the DESCENT.HOG and DESCENT.PIG files from version 1.5 of Descent. One other thing to note is that you may need to turn the music off, or else it tends to freeze with a blank screen when loading levels. It also tends to turn the music back on again when you restart the game.
Descent runs rather well on the DS. The controls can be a bit 'challenging' though, since it uses a fair number of buttons, many of which can be difficult to reach while steering via the touch screen. You'll probably find it beneficial to remap some of them.