Having said that - none of the current electronic viewfinders that I've seen come close to an optical viewfinder. This isn't going to happen soon.
You haven't seen the A77's...

Sony's kit 18-55mm is not a good example of compact lens. Check out the Olympus 14-42mm, now THAT is compact. Making the shorter back-focus does allow manufacturers to make smaller, more efficient optics. Though again, you can't really tell based on Sony's 18-55.