The XZ-1 looks good, but there's no viewfinder. As a DSLR user who looks to switch to a smaller camera, I'm just not going back to the camera-at-arm's-length-to-view-the-back-LCD thing to take my photos.
The Fuji X100 is the only large-sensor prosumer camera that has a built-in viewfinder (attachable viewfinder is out of the question as it doesn't give you a true enough preview), and so it's the only one I'd be willing to switch to. Come to think of it, the new Sony NEX-5N has an electronic viewfinder that might work, actually.
An attachable electronic viewfinder might work, but then you can't use an external flash together with the viewfinder. Plus, it's just one more accessory you have to buy and carry around with you. Pretty stupid.
The Fuji X100 is the only large-sensor prosumer camera that has a built-in viewfinder (attachable viewfinder is out of the question as it doesn't give you a true enough preview), and so it's the only one I'd be willing to switch to. Come to think of it, the new Sony NEX-5N has an electronic viewfinder that might work, actually.