Thats the point CyberStretch. To do it your way you still have to have Poser, this application doesn't really compete with Poser. But if the competitor can read Poser files and work with the data (joints, materials, ...) you don't need Poser anymore.

CyberStretch > except for the portions of Poser that cannot be exported.

Every functionality which is in Poser 4 is available in decent 3D apps. Every new functionality of Poser 5 is also a part of some 3D apps or as external plugin available.

To say it again: Poser 5 doesn't exist in a vacuum, all the features are available elsewhere. Posers strong points are the (cheap) prize and the third-party content.