The Mac generally plays very nicely in an enterprise environment: simple binding to AD, users can be denied admin access without compromising their ability to join networks, change the time zone, add printers, OS updates can be managed and delivered from local servers rather than each machine going out to Apple to download the same patch, and machines can be set up rapidly from a standard image using target disk mode.
The MacBook Air can live nicely in an enterprise environment too, but its limited port count poses some particular challenges, mainly that no FireWire means no target disk mode, and the particulars of its ROM mean you may need to augment your base image slightly. Having said that the new MacBook Air ships with a USB boot disk, which means you can rapidly boot the machine, attach a USB hard drive with your image on it, copy that image to the internal drive, and reboot.
The MacBook Air can also be effectively managed by Casper and imaged over Ethernet – the USB Ethernet adapter is for the most part identical to a physical Ethernet port though from time to time I have seen them lose connectivity – by netbooting the Air and running the Casper imaging process.
The main issue may be your support staff’s unfamiliarity with the system since many standard support procedures will expect an Ethernet port, a DVD drive, a FireWire port, etc. – the more important question, however, is why not get an iPad and a much more powerful full-size laptop or desktop Mac for the same money!