I currently have the original MacBook Pro (1,1) (1.83 GHz Core Duo, 2 GB, 500 GB Seagate Momentus XT). One area that I am not happy with is the heat produced by the machine. After extended periods of light activity (web, programming, etc) or when watching web videos even for a short period the machine gets extremely hot. This is obviously most noticeable when the machine is on my lap. So my question is do the newer machines such as the i5/i7 MacBook Pros or the newly released MacBook Air have these heat issues? How does the heat output between the MBP/MBA compare? This site seems to provide some information: http://www.intelmactemp.com/ The numbers there show that my current model averages around 50C/75C (idle/load), the early 2010 MBP i7 at 41C/86C, but does not have any data regarding the MBA. These measurements give me some idea, but how do the machines actually feel on your lap? Thanks for the help.