Here's photo of the Prius coupe. I highly doubt it will actually look like this since it's way too futuristic and crazy looking. But if you imagine it toned down, you have yourself the Prius coupe production model (or what it could look like)
Prius Coupe VS Honda CR-Z will make for a good battle. Toyota better hurry up with this idea and get it into action before Honda takes the spotlight. The CR-Z is slow but people still love it, and it's getting performance improvements.
What are the chances of Lexus making a compact luxury coupe based off of the Prius? I bet not everyone will like how basic a Prius is but will love how compact it is. People will want fuel efficiency, luxury, power everything, cool gadgets, etc, that's where I think Lexus will step forward.