The D2 comes with 4Gb built in.
It also has an SD Card slot. At release it supported cards up to 4Gb.
Some people are already using the latest beta firmware with 8Gb SDHC cards, for a total capacity of 12Gb.
Soon 16Gb and even 32Gb cards will be available. SDHC cannot go beyond 32Gb.
Does anyone know if any manufacturer is planning on releasing a 12GB (or even better, 15GB or more) flash memory digital audio player within the next year? The TrekStor Vibez is listed on CNET as a flash player but actually contains a hard drive.