I have a DS. I think it is better for playing roguelikes mainly for the touch screen, that can come really handy... I hope more developers start developing for the DS!
Right now there is POWDER, Nethack and Crawl. I'd love to have Angband too...
Here is more info on the DS scene:
http://nintendo-ds.dcemu.co.uk/nintendo-ds-homebrew-games-35334.html...emulators for the DS, homebrew games, etc. That page is actually for Nethack DS, but you can take a look at the menu on the left for lots of more things
So come on, devs, start porting already!