Here are 4 pictures taken with the front facing camera while holding the iPad in a comfortable viewing position using 4 different orientations. Note how crap the framing is in each one (and how the eyelines are way off for all but the bottom-right, in which it merely looks like I am staring at your neck rather than over your shoulder).
Compare these with Apple’s obviously bullshit sample pic from their website, in which the dude’s eyes look squarely out of the screen. Not only does the framing suggest he is talking to an iPad mounted just beyond arm’s length in front of him (on some kind of tripod on which the device is either perfectly vertical or tilted slightly forward), but his eye-line suggests that instead of looking at the face of the girl he is talking to he is instead staring determinedly at the tiny lens in the top of the bezel (ironically, the only reason to do this is to appear to be meeting her gaze).
Talking to someone in real life who won’t make eye contact is disconcerting at best; add into that low quality video, slight lag and the “I’m yelling so you can hear me” voice and Facetime becomes the least useful iPad app I have. Until someone works out how to mount the camera in the middle of the screen I really can’t see it being comfortable to do face-to-face video chat with a large tablet.
WWDC Update: Oh look they’ve doubled-down on the fakey bullcrap with the iOS6 preview site by showing Factime in landscape orientation, which really is impossible to use in real life.