As I well know, Badspot is no fool, if he think he can make the game far superior by having a stronger engine, I'm sure he will. I said far superior for a reason. If such a change only minorly helps who cares. You shouldn't say its not going to happen just as it stands, the majority doesn't need a better engine.
Like who builds up to 256,000 bricks anyhow. Most of the most interesting builds have 50k max.
Not allot of people have extremely complex models for their minigames.
And as for cosmetic appeal, shaders is fantastic and doesn't need a new engine. I'm sure other graphic changes won't as well.
Besides, Badspot rewrote, and wrote lots of changes to get shaders going. He is probably well capable of streamlining this engines code and making it better to what it is now. Who needs to spend thousand some dollars on something you can do for yourself.