I could use - and many others have requested it - a transform shader, i.e. a four-point corner pin for skewing surfaces. I'd also love to see some sort of customizable mesh warp, think a grid 3x3, 4x4, or 5x5, of points, where each point acts like a corner pin. So people could customize their distortion patterns in more detail.
I also want these distortions to have an option to be able to distort whatever is behind them, even if the object behind it is moving. So you could have a distortion cast from one (partially visible or invisible) layer onto the layers underneath it?
I have several projects - 2d with a few pseudo-3d effects, that would benefit immensely from these shaders. I am looking at 3d engines if necessary but if these effects can be done in C2 instead it'd save me a ton of time and labor.