Those back-only mounted mic and speaker jacks. There should be a Headphone jack on every computer front now. Heck even eMachines has them on them.
Also, a few more Front-USB ports would be good to. At least 2. Sure, I understand MOST things will be used continuously, those should be in the back. But for things like Tablets, Cameras, hand scanners, Keyboards(musical that is), personal juke-boxes (the Archos comes to mind), memory storage devices. ALOT of things will begin to need front mounted USB ports.
Frick, we could go to all USB for HID, or even all devices except for network and internal storage. When they finally work out a couple of minor things then even those could be USB.