I'm conflicted also. I crossed shopped the 2012 Impreza 5 Door CVT & the 2012 Focus 5 Door auto back to back over the weekend and having the same concerns about the Impreza mpg discrepancy. I liked them both for different reasons.
The Ford Focus mpg numbers on Fuelly seems to be coming in fairly close to the posted EPA ratings. Maybe the Impreza will pickup as more are on the road and reporting on Fuelly.
I really need to decide how important mpg vs. awd is to me. I'm hoping to see better mpg numbers in the near future from the Impreza b/c it's a very appealing package.