In version 8, you can now rotate power supplies, as shown below:

To rotate a power supply, you can either use the normal bottom middle Rotate Handle, or enter a rotation angle in the propery bar. The rotation angle for power supplies behaves differently for other graphics. It will apply the rotation angle to the power supply drawing, which is attached to a power supply object. The power supply object contains the stats for the power supply, but the power supply drawing is separate and can be positioned above, below, to the left or to the right of the stats box. So the four commands in the PS menu starting with "Drawing".