MacBook Air Target Disk Mode

Target Disk mode is such a useful thing to have on a Mac.  In fact it’s the number one I think when dealing with problematic PCs … “If only I could put this thing into Target Disk Mode”.  The MacBook Air is a worrying development because of the lack of firewire it would seem TGM is not an option.  Of course this could be easily solved by Apple creating a USB TGM.  Rob Griffiths from MacWorld reports that an Apple rep told him there would be no such thing on the MacBook Air.  Has anyone had a go with rebooting the MacBook Air and holding down the “T” key to see if it still has the firmware capability of booting in TGM?  Or at least whether it has the option in Startup Disk in the System Preferences.Surely USB TGM is not that different?  As I understand it TGM goes back to SCSI anyway and was ported to Firewire – if Apple is insistent on replacing Firewire with USB surely it is only a matter of time?