kazimier:
as it seems like a natural progression to allow for wireless control with the same capabilities as the wired option,
Unfortuantely that's an assumption that quite a few people make (me included ;-). The ArdOSC library uses some low level functions of the Ethernet library that "talk" directly to the Wizenet W5100 chip on the Ethernet shield. Using a different Ethernet shield, whether WiFi or Cable, that does not use this chip will most likely require you to find equivalent software functionality for that different chip that you can adapt the library to.
If you don't have that skill level ( I don't) then there still is an actually very simple WiFi solution that works perfectly for my project. Unfortunately, for now, you'll have to toss the WiFi shield and use a standard Ethernet shield, connected to a little pocket Router such as the TP-Link WR702n (approximately $30). My projects employs a Teensy++ 2 Teensy USB Development Board and a WIZ812 Ethernet Module http://www.saelig.com/product/ETH042.htm with the adapter PJRC Store. I am not trying to sell anything but listed these parts simply to help explain that I am not just suggesting something that may work but actually does work in my project.
The ArdOSC library is not the only library that depends on this low level functionality, btw, the DHCP/Bonjour libraries for example depend on the same low level functionality (w5100.h, w5100.cpp in the /utility subfolder).