Here is a mockup of a Cycles Voxel Data Node
It is very similar to the voxel data texture from BI, in fact behind the drop-down there should hide the same options as in BI. The key difference is that there should be the possibility to offset smoke data just like you would offset image sequences. This would make the option to chose the domain from where the actual data is loaded more useful. For example if you have multiple chimneys in a scene one would need to bake only one simulation. By offsetting the data for each chimney a little each column of smoke would look a little different.