If this could have multisample support it would be very helpful indeed. While simple drag and drop allows for quick and easy track level composition, multisample support would broaden its usage considerably.
16,24,32 and 64 bit file support would also be a good idea as it will mean the zSampler can play back any type of bit depth that Podium currently supports.
Graphical editing would be another nice feature that would make it a much more flexible tool.