Wow! What a great reason to avoid buying new server hardware from HP! It is a massive disincentive to purchase. I cannot help but think this is supremely short sighted and a decision made by somebody up high who is not technically inclined.
I suspect that the real reason that they have dropped wireless networking support is that Nintendo screwed up, royally, with the original design. The present Wii has an 802.11b/g wireless adapter built-in. Due to flaws in its software implementation, however, it is only capable of working when the 802.11 (legacy mode) basic rates of 1 Mb/s and 2 Mb/s are advertised by an access point. This means that 802.11b support, an additive amendment to the 802.11 standard, must be enabled on an access point for a Wii to be able to connect to it. As a cost cutting measure, the drivers were embedded in to the games themselves making this largely unfixable without some incredibly ugly engineering hacks. They have obviously decided not to bother. See: http://nostringsattachedshow.com/2012/01/18/nintendo-vs-cisco/