I understand the reluctance to put external brakes on the casters as they are usually unattractive but for $400 Apple could have easily not mailed it in and designed the coolest braking wheel ever. Something along the lines of pushing or twisting the metal hub to lock the wheel. A simple cam lock like the internal access on the Pro or a soft touch push-in of the hub. Could have done something truly unique befitting a $400 price. Like many things lately Apple misses a lot of opportunities to wow people and usually those things are the small things like a caster or a pulsing sleep light, etc...