Level 5 has always been very successful with their games... Layton... DQ for PS2.. DQIX for DS... And that forgot what it was called... pirate's galaxy or something liddat game for PS2.
Fun, I wouldn't know, but they have plenty of commercial success to continue making plenty of good games liek this for the DS.
Though with their releasing of 512MB... I think lots of people are going to push the game makers for games with more content. Maybe Pokemanz? More detail for every pokemon or something like that. Either way, its as exciting as A.S.H having 256MB.