It would be nice to have more grab points to move the models... in most poses you can grab the arm or leg and pull it around to some effect. But it would also be nice to be able to grab the head or hips to move the model around.
Head grabbing would lead to obvious and hot results, and the head and neck joints already seem to have pretty good limits for range of motion (as noticed with head tracking when you try to get a BJ with a large tool, her head snaps back but not too far). I really want to grab lovely Tiffany's head.

The hip grabbing might be a little tricky as the hips seem anchored (with just a little give before they reset) in most poses but would lead to more fun and flexibility. Even if we can only manipulate the hips on one axis (with the mouse wheel after a grab perhaps?) it would be tremendous. For example in Dark Dreams Sam's doggy pose is pretty low to the ground and its hard to get vaginal we grab hips and in that pose can push her hips lower or lift them higher, meanwhile in the cage you could pull her hips back toward the bars for other play (this one might not work that cage is pretty cramped). Another example with one of Jenna poses she is sitting too far back on the bed to do many things, for that pose an ability to drag her hips forward toward the edge of the bed would make this a much more versatile pose.