Could they rip off the layer effects feature from Photoshop? There is a plugin for it but it's honestly pretty useless. It takes forever to generate the effects, you can't edit them afterwards and they are on a separate layer.
They needed to implement GEGL for all image operations, now that this is done, we might actually see "live" effects on layers in future.
well, all it takes is for someone to tackle it, seeing as how the project is open source.
What I really want to see on GIMP would be a rip-off of content aware fill. I'd really like to have a look at how it's done. Obviously I can't look at Adobe's code.