In Vue (and Lightwave, 3DstudioMax and others) you do not actually import and use Poser files but instead use Poser itself hosted in the other application (posing is done by Poser and the static object is made available to the hosting program).
In all these applications (and many others) you can of course always import the static object.
In Poser, DAZ Studio and Carrara 6 the actual model is imported and can be posed.

Morph files are something different as they are in effect patches applied on a (static) object. Many programs can apply morphs (or patches) and often have some means of indicating a weight for this (be this a dial, slide or numeric value).