more info here
http://www.planetgamecube.com/news.cfm?action=item&id=5611
The IS stands for Intelligent systems and it's still code-named nitro.
They haven't gotten around to giving developers the new model yet.
http://www.planetgamecube.com/news.cfm?action=item&id=5611
This is a more advanced unit than the bare chipset originally released to some developers. Functionally, they are similar except that the cased emulator supports the touchscreen feature on the included DS prototype (still in its E3 form, as you can see). We are currently unsure of how touchscreen features are tested on the old version; perhaps the display is shown on a connected PC and can be manipulated with a mouse or PC touchpad input. Regardless, this newer emulator accepts direct touchscreen input just like a normal, production DS, making it easier for developers to understand how players will interact with the touchscreen.
The IS stands for Intelligent systems and it's still code-named nitro.
They haven't gotten around to giving developers the new model yet.