The reason DAZ didn't develop for Poser 5 was that they didn't have a copy of it. And they didn't have a copy of it because of a controversy with CL over the Poser 5 EULA (End User Licence Agreement). The nature of this controversy has been speculated about in lengthy posts here and in other forums, let's just note that it's over and done with. The EULA is changed. DAZ products works just fine with Poser 5, according to my experience. However, it seems that DAZ does not develop anything that utilizes the Poser 5 specific features such as dynamic har and cloth, probably to ensure future DAZ|Studio compatibility.