As a synthesizer geek I'm really enjoying how Amberlight works, a bit like a visual synth. Along those lines I would love the ability to automate/animate more parameters such as the Contrast and Filter settings, and H-S-L. Freely assignable modulation envelopes or even LFOs would be nice too. Plus more Filters/FX. Plus more waveforms for the Wave Modifier, including noise.
It would also be great if GIFs could be imported, rather than having to use the same back-image in every frame. This would add a lot to the animation potential.