I contacted Samsung directly as Bagsy1 did before and got the same reply, I then queried it as the network provider isn't relevant (as we've mentioned) and its been some time since it was initially released. I've just receive their reply which reads:
In response to your query, the information you have provide is correct, the updates have been released for some devices in the UK.
However we cannot confirm when it will be available for your device, the updates are rolled out by device serial number and location, unfortunately we are not able to see when they are due to be released for individual devices.
I apologise for any inconvenience caused.
It surprises me that they are releasing it in batches within the UK as, although I'm sure they've had good sales, have they had enough to merit a staged release? Also, surely a staged release would mean at most a few weeks between release batches and not months.
Looking back through this thread, it does seem though that all the posters from the UK are still waiting for the upgrade