The current DS software supports DSD64 and DSD128. The Bridge II supports DSD64. The DMP supports DSD64 and under some circumstances DSD128 (different versions of the software do DSD128 a little better or a little worse.)
The Bridge II will never support DSD128. I doubt, (but don’t know for sure) that the DMP will ever support DSD256.
The DS hardware could support DSD256, but that’s not trivial. The FPGA is essentially DSD256 inside, but getting DSD256 to the DS would take new USB code in the DS, new USB drivers for Windows, MAC and Linux or I2S. Many I2S sources can’t do DSD256, but that out of PS Audio’s hands.
PS Audio wants to support DSD256 where it’s possible, but I don’t have any idea when it might happen.