Personal Hotspot was introduced in January 2011, so 4.1 onwards.
No it wasn't.
Personal Hotspot was added with iOS 4.3 for the iPhone 4 in March 2011
Verizon iPhones originally shipped with the feature enabled in iOS 4.2.5 (not released for other devices).
"Internet Tethering" was introduced in iOS 3.0, but that didn't allow you to create a Wi-Fi hotspot.
The feature has always been dependent on your carrier:
a) Supporting the feature
b) Allowing you to use it on your plan
In the case of Orange, they may have changed their policy on tethering.
I don't recall the specific timing, but introduction doesn't mean availability.
That said, there are other countries where Orange is available. Starting with Orange France, Orange Mauritius etc.
Since I upgraded to 5.1, I have noticed the personal hotspot option is available.
Previously it said 'contact Orange'.
Anyone else had this?