Dev:Ref/Proposals/UI/UV Canvas Rotation
Proposal
Allow rotation of the UV editor canvas. This will allow painters/texture artists to do freehand strokes much more easily while texture painting and encourage hand painted texture artists to stay within Blender for texture painting needs.
Keybinds
This be done with the same hotkeys that control the 3D viewport.
MMB would allow rotation of the canvas shift+MMB would still do translation ctrl+MMB would still do zoom
Reasons It's needed
When you write or draw on a piece of paper, you will notice that you often rotate the paper to reduce strain on your wrists. You will also probably notice that it is easier to draw a controlled line at an angle, while vertical or horizontal lines are more difficult to produce. Allowing the rotation of the canvas allows the artist to draw in a position that is most comfortable to them.
Edit
I don't see how this improve the interface any, rotating the image does not effect the stroke angle for a mouse input at all, as it is completely relative to the screen orientation, as I think most serious painters will be using a tablet; rotating the tablet to the desired angle effectively accomplishes the task. That being said, a rotated view might be good to correspond to the tablet angle better.