I've thought about creating a pokedex for the DSTwo, but the biggest deterent by far is collecting all the information for each pokemon and organizing it in such a way that can be easily parsed. Only a few template entries would be needed for the actual creation and testing of the pokedex, then i suppose the rest could be added by users. With this type of setup, it wouldn't be hard to add newer pokemon as the games are released, rather than waiting for an update in the program itself.
If anyone is interested in helping to get the intial stuff prepared (interface ideas/mockups, all possible information for a couiple of pokemon, sprites), I'd be more tempted to have a go at this.