First, there is no such thing as 802.11x - the correct name is 802.1x - and the protocol is a full security protocol, not a port restriction mechanism.
Secondly, there is no mention of IPSec - a major player in security that covers both wired and wireless networks.
Lastly, the article seems to assume that you have only mobile stations connected to a single wireless access point that is itself connected to a wired network. None of these are necessarily true.
Indeed, this is why there are over 150 routing protocols defined for wireless networks, and why the IETF have two working groups - one for mobile computers that may move between wireless access points, and one for where an upstream router may itself be a wireless device.
The article, as it stands, would make an excellent first chapter (if the 802.1x error is fixed) for a much longer piece that covers the different types of mobile scenario and what needs to be done in each.
However, as a finished piece, I can only give it a 5/10.