In so far as VOR is the locational analogue of traditional "rotating beam" radar, but there the similarity stops. VOR has a known structure to its intended transmissions. Passive radar relies on incidental transmissions, and the system learns about any structure in the received transmissions. Passive radar has potential for much greater accuracy (better than GPS??), as it can potentially use a huge bandwidth.
http://en.wikipedia.org/wiki/VHF_omnidirectional_range