I'm considering developing a shield that converts standard AC mains to DC. The shield would have 3 outputs: 5V fixed, 3.3V fixed, and 6V-12V adjustable up to roughly 5A.
It would use a quasi-resonant flyback converter for the adjustable 12V and linear regulators for the fixed outputs.
I'm curious to see if there would be interest in this design from the arduino community.