Wireless security... What?
This is getting ridiculous: an Internet search on "wireless security" returns over a million results, while "wired security" is fetching much less, and the results aren't much to do with transmission of data over networks.
There is no difference in wireless and non-wireless security. Layer 1 of the OSI model - the Physical - is in question. Anyone who assumes their physical layer is secured (e.g. no one can wiretap etc) should ask themselves a question - what makes them so sure? It is not a trivial task to locate a wireless bridge opening the network to external connections; it takes much more effort and sometimes very sophisticated electronics to find wire taps.
You should design infrastructure and applications as they were residing on public Internet. Saves a lot of grief further down the road.
Back to wireless security. They have some good ideas, like 802.11i - the security suite that requires endpoint authentication and encrypts traffic to the access point - however, that just highlights the fact that corporate switching and routing infrastructure too often is considered secure. What really makes a difference is wide adoption of secure configurations of wireless networks. Therefore it's time to shift the emphasis from wireless back to OSI levels 2 to 7.