We've already seen the final logo and expansion symbol for Unhinged, but those were not the only ideas, by any means.
Here are some of the other ideas proposed for the logo design (thanks to Magic art director Jeremy Cranford for providing these):
This last logo was pretty close in spirit to the final. For comparison, here's that final logo again in full color. (Note that you can win an eight-ball life counter at an Unhinged release tournament near you.)