The DSi category of the ESRB's database is currently pretty small, containing only eight games, including some of the current first-party DSiWare (not all of the existing games are visible yet), a few Gameloft games (Brain Challenge, Real Soccer 2009, American Popstar Road to Celebrity), and ... three Atari games. Specifically, Ghostbusters, N+, and The Chase: Felix Meets Felicity, all of which are now listed as both DS and DSi games.
These are the only games in the whole database to have such a distinction -- and the only DSi-listed games that aren't downloads. Unless they are!
We don't want to be rumormongers, and we don't want to jump to conclusions, so we'll lay out the possibilities that have occurred to us, from most exciting to least exciting:
Atari is planning to digitally distribute DS games via DSiWare, starting with Ghostbusters and extending into its back catalog.
The publisher will release special DSi-enhanced cartridge versions of the games.
The updated listings are a mistake.
Atari PR had the following to say in response: "Unfortunately, no official word from Atari. We'll let this stay a rumor for now ;)" %Gallery-27664%