It seems that Realtek's dropbox tarball isn't compatible with Linux 3.8.*. Larry Finger, a noted developer working in the wireless branch of the kernel, has put up a new driver on github.
To download and compile the driver, you need the
git software, and packages needed for compiling software:
sudo apt-get install git build-essential
Then you need to download the software:
git clone https://github.com/lwfinger/rtl8723au.git
After that, compile the software and install it:
make && sudo make install
All the commands together for convenience:
sudo apt-get install git build-essential && git clone https://github.com/lwfinger/rtl8723au.git && make && sudo make install
After a reboot, wireless will then work. The driver will have to be compiled and installed (
make && sudo make install) every time the kernel is updated.