Finally got the update come through tonight.
I didnt notice the phone telling me it was available until Zune mentioned it, then lo and behold, I unlocked the phone and what can be described as a "drop down menu" was showing saying that an update was available.
So, ye, installed. Internet sharing on orange is working for me, my old iphone with no sim connected through it fine.
Looks like a few of the minor changes come through randomly after a while. The "nokia-specific" marketplace live tile change didnt occur for about 5 mins. So looking forward to testing out everything tomorrow.