I don't understand. Do you want to plug a wifi adapter into your ethernet port so you can get 802.11ac? Apple released one of those adapters yesterday (http://www.apple.com/airport-extreme/). Set it on your desk and run an ethernet cable from the device to your computer.
The news here isn’t that Apple will stream the keynote. The news is that this is another example of the app as a channel. If Apple is going to take our TVs down that road, this will serve as a demonstration to the media giants that Apple's technology works.