My research has shown there are 2 reasons any device would use this technology. I am going to explain both but ultimately I don't know which is relevant to you (sorry). It is not about connecting to the internet, it is how the device connects to your PC or how the device connects to a monitor which is too far for a cable.
This is easier to visualise if you think that your graphics cards is external.
Long term I think this will be more popular (having external cards) as they will have their own dedicated psu, ram, cpu etc and things like thunderbolt will make this happen but this is off the point. :)
So if you have a graphic card which could be placed internal or external you can now choose how to connect it to your pc... Wired or wireless. Well, this would make sense if it was WLAN but it is WWAN so my guess is it is an attempt to make the unit as stand alone as possible. Maybe the card has a unique IP and even a web page for remote management or independent updating? Maybe it is used for sending out reports, I really don't know.
Now I think this bit is more relevant to you. To focus more on the connectivity you can also use this to send video wirelessly. So your PC could send your video to another device in another room of a house, like your TV. I would imagine it is useful in conferences where you want to do a presentation but instead of having to get all the cables plugged in, which trails the desk and floor, you just connect like it was a wireless router.
http://news.techworld.com/mobile-wireless/10900/vendors-to-show-first-wireless-graphics-card/
http://m.pcgamer.com/2011/01/13/nvidia-release-announce-wireless-graphics-card