I just got off of the phone with RIM and after *****ing about their troubleshooting (I am a networking professional and they keep trying to say that the wifi network is the issue, BS, my network is better than perfect) but I had my ticket escalated and I have a method for manually updating the Playbook using the Desktop Management Software.
First go download the Blackberry Desktop Management software. Here is a US link to the software:
BlackBerry - BlackBerry Desktop Software - BlackBerry Software at BlackBerry.com
*NOTE* When you first plug your playbook into a computer it will automatically want to install the BLACKBERRY DEVICE MANAGER which is different from the BLACKBERRY DESKTOP MANAGER. *NOTE*
Once the software finishes the installation and the computer restarts, open the software. The software will take a while to open but once it is open you should see a screen that says something to the nature of plugging in a blackberry device.
*NOTE* THE PLAYBOOK HAS TO BE TURNED OFF FOR THIS TO WORK. I WILL REPEATE MYSELF, THE PLAYBOOK HAS TO BE OFF FOR THIS TO WORK. *NOTE*
Connect the turned off playbook to the computer using the included USB cable. (WHEN I FIRST PLUGGED IT IN IT HAD TO INSTALL MORE DRIVERS, JUST FYI) Once the tablet is connected a window should come up saying that the software could not communicate with the device and you have three option at the bottom of the window: Try Again, Update Software, and Cancel.
I was told on the phone that pressing the Update Software button would force an update to the device through the computer and this would in turn bypass the issue with connection the device to wifi to download the software update. I am in the middle of downloading and installing the update right now and everything seems to be going fine for me. Wish me luck and I hope this helps!!