To have the honor of the first dual-screen phone, I would expect a lot more from it. The Evo was well worth the honor of the first 4G phone. According to a few hand-on demos, it isn't as fast as it should be. This phone needs some dual-core, video-calling, 4G love. The "tablet mode" that you see above puts the full size at 4.7". That makes it barely bigger than the Samsung Infuse. They should have made the individual screens bigger the iPhone size.
That screen break in the middle would throw me off. While most apps would be viewed across both screens, some cam have different functionalities for both screens or you can run two apps at once. Running two apps needs that dual-core. Give it some better specs, bigger screens, and a manufacturer (HTC preferably) that will give it OS updates past froyo and I might consider buying it.