I have also a new MapBuilder update ready since Sept 2015, but I always postpone fixing some bugs, because the state of 3dgs is not really motivating, contrary to the engine I currently use in 2 projects...

apparently gamestudio developers has chosen not to step forward to avoid the decrease of users caused by the increased competition. sadly it was 4-5 years ago. I don't think it can be popular again, when you can get up-to-date professional multiplatform tools for free, beside more support (tutorials, assets). maybe you can start with them slower than with 3dgs, but finally your game development is going to be faster.