talk is there's movement now to offer DSD (sacd) downloads too. unless someone has a bunch of sacds, the argument for getting a new sacd transport seems to be getting weaker and weaker.
however, having said that, not all dacs and digital interfaces are created equal. for example, you're not going to get the same performance as a transport when you use a pc and a usb interface unless you have the right usb implementation that significantly reduces jitter. in my opinion, for usb, i would only go with a dac that has built in two-dimensional jitter reduction like the playback designs dac or, if the dac didn't have this, then a dac in combo with an empirical audio usb converter that reduces jitter.
however, having said that, not all dacs and digital interfaces are created equal. for example, you're not going to get the same performance as a transport when you use a pc and a usb interface unless you have the right usb implementation that significantly reduces jitter. in my opinion, for usb, i would only go with a dac that has built in two-dimensional jitter reduction like the playback designs dac or, if the dac didn't have this, then a dac in combo with an empirical audio usb converter that reduces jitter.