With little airflow, dust will take a while to get onto components. Plus, being out in the open, there's nothing stopping the air from escaping, unlike a conventional case. Good idea, just not made too well at the moment. Just get a case with good airflow (Antec 900, 1200, Coolermaster Cm-690 etc) and some dust filters for intake fans and you can make a bloody good computer with minimum case an component temperatures. Also, to anyone not using Artic Cooling MX-2 thermal paste, GET SOME! Reduced idle temps from CPU from 35C to 27C and load from around 50C to 43C... Bloody good stuff. Was using artic silver 5 before hand on a Intel Q6600 with artic cooling freezer 7 cooler.