I'll chime in to say I've been watchless since the rise of smartphones and it wasn't until fitness trackers (Misfit in my case) that I saw a cause worth an extra device on my wrist. My interest in possibilities expand here with a real platform (though is potential at this point), while my concerns point towards the battery-life (sleep tracking, for instance, is going to be difficult). We'll see. EDIT: For those wondering about the size choice, the below instructions allow you to virtually compare on your wrist. Download Apple Store app on iPhone. Open the Apple Store app, tap the ‘Learn more’ link under the Apple Watch banner at the top, tap the ‘View Pricing’ button on the top right corner, then tap ‘Compare case sizes’ near the top center. Place phone on wrist. Looks like I'll be going 38mm.