Here's an idea for a new Eyedropper-like tool: drag the Peeler across the canvas, and Photoshop will generate a gradient to match. A circle or bar near the cursor keeps track of what colors have been picked up.
You can choose between different levels of complexity, from a two-point solution to whatever limit happens to exist for gradients. When used on a single layer, it can pick up transparency. You can pick whether the gradient points are evenly spaced, or follow the chosen drag area.