Given that DSD256 seems to be the high resolution preference for a number of music downloading sites (High Definition Tape Transfers, Native DSD, Blue Coast Records …) I thought I would start grabbing those when available in the hopes that Ted may provide for this as an I2S option in a future release in the DS. (Fingers crossed.)
Got my first DSD256 recording yesterday and used the free Tascam Hi-Res Editor (http://tascam.com/product/hi-res_editor/downloads/) to convert it to DSD128 for the DS. Very simple interface. (For those running Linux, the Windows version ran just fine via Wine.) It can also convert to various PCM as well.
Each music file must be loaded individually, which is a little tedious, and takes a few minutes to convert, but the results sound great.