From a UK perspective, but interesting none-the-less:
http://www.fleetnews.co.uk/news/2010/9/27/exclusive-nissan-leaf-rvs-announced/37795/
CAP's Mark Norman told Fleet News: "The Leaf should have a shallower depreciation curve than conventional cars; the electric motor has fewer moving parts than an internal combustion engine so when mechanical issues and wear and tear begin to affect other cars, the Leaf should still be running well."
http://www.fleetnews.co.uk/news/2010/9/27/exclusive-nissan-leaf-rvs-announced/37795/