Yeah, I am pretty disappointed in Nintendo. The Wii and the DS are both amazing machines with great potential, but... well... yeah. I love my DS, the best handheld gaming system ever produced IMHO, but there are actually VERY few real DS games of any interest to me. Sadly, to unlock the true greatness of the DS, some way of playing homebrew is required. Now on to answer Nanner's question.

No, The Secret of Monkey Island was never released for the NDS. Neither was Metroid II (and the DS can't play the good ol' monochrom GB carts), nor was Super Metroid (though it really should have had a GBA rerelease, and it is truly ashame that it did not). Via SummVM for DS you can play all those old LucasGames adveture games, including Loom, Maniac Mansion, Monkey Island 1 and 2, Day of the Tentacle, Sam & Max Hit the Road, the Indiana Jones adventure games, and any other of those older classics that ran on the SCUMM engine that I am forgetting. It can also run a good deal of non-LucasGames/Arts adventure games. They run flawlessly on the NDS. Unfortunately games like Monkey Island 3, Full Throttle, and Grim Fandago do not work though. I would have loved to play those on my DS.

And of couse Metroid II (in full color) and Super Metroid are made possible to play on the DS through emulators.