You can absolutely keg cider. I've kegged mead and I know people who keg the island mist wine kits to carb them up.
Cider is usually a higher CO2 volume than most beer though, so aside from balancing the tap line so you can carb and dispense at that higher psi, there's no issues.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10