In the PSP when sony released newer firmware people were able to take it and merge parts of it into an older firmware and then successfully flash the device. The only thing I could see holding it back on the DS is maybe a smaller firmware capacity on the DS. If there is a smaller size on then maybe one could link certain pieces of the firmware to slot 1 or slot 2. Either way I would not give up hope for a DSi firmware on the DS.. but I would forget about the cameras.