What I would love to see is:
-DirectX 11 support (as I already mentioned some time ago)
*support for geometry and tesselation shaders
-The possibility to render into a depth texture which can be used for shadow sampling for much cheaper PCF and thus a lot faster shadows.
-A new WYSIWYG WED.
-Culling of objects hidden behind terrain.
-more basic, easy to use templates, something like the A5 ones, but cleaner
-better shader library
-some pretty default assets

What is great about gamestudio is that you can actually learn a lot about game development and programming with it as I and probably many others here did, because unless engines like Unity it feels much closer to what is actually happening and still the API is much easier than those of most other engines.
Sure in other engines, you can just use stuff and it works, but most users will never understand what is actually happening there.
Also programming for gamestudio is fun, much more fun than with any other engine I used so far (Unity, Shiva, Irrlicht), not to mention the really streight forward and great to use post processing system.