It'll work fine. The Netgear will simply plug into a spare ethernet port and should work without any changes needed. You will want to butchers at the instructions and/or run the disc supplied to get your wireless network encrypted, preferably using WPA-PSK.
One thing worth noting is that proprietry equipment such as Netgears Rangemax is designed to work with Rangemax equipment on both sides of the link. Although a standard 802.11g wireless device (such as the Wii) will work just fine, the extra dollars you spent on getting a Rangemax device will be mostly* wasted. You may as well opt for a cheaper, standard 11g access point.
* I say mostly since companies such as Netgear claim that technology such as Rangemax does indeed improve the performance of standard 11g devices too. I've not seen them make much of an impact myself mind.