Attached jpg screenshots of what my folders looked like before each update and the WP7 Update Cab Sender windows...
I installed 8779 and 8783 at the same time along with the English - United States (0409), Spanish (0C0A) and Chinese (traditional) (0404) language packs
I installed 8858 with the English - United States (0409), Spanish (0C0A) and Chinese (traditional) (0404) language packs
Here's the process I followed:
1) Disabled lock screen password (just seemed like a good idea)
2) Start Zune desktop application, sync files, close Zune
3) Run WPSupportToolv2 (I ran into an error without installing it)
4) Run WP7 Update Cab Sender Tools
5) Start WP7 Update Cab Sender, select L to read logs - verify connectivity
6) Select B to backup and send files
8) Be patient
9) Repeat once
10) Enjoy WP7.8
I hope this helps someone.
Wifi sharing options look the same, don't see any changes.
The icons got HUGE after the update. It's going to take me some time to cuztomize it.
Phone seems zippy. Office docs opened quickly.