I want to try and lend a bit of perspective here, based on experience with cloth simulation in various programs. I can take most Poser clothing into LW and set it up for cloth simulation just fine; as long as the clothing envelops the figure, it can be set up for dynamics. It usually has to be subdivided of course, because cloth simulation ultimately needs a ton of mesh resolution to create folds correctly. Poser 5 could for instance, simply allow you to set a certain material to use clothsim. Which would mean you could likely be able use any existing clothing. Or it is possible existing clothing will need an update to designate areas affected by the simulation; and the parameters of what kind of cloth. Both scenarios are of course speculation. However, just because a program has cloth sim does not mean that clothing modelling paradigm is completely changed. We are still using polygons, that are still modelled to look like clothing, that are still modelled as a "shell" around the figure. These same kinds of meshes will simply behave differently once in use.