Not sure there is enough there to get me to upgrade my Nexus S but then again mobile phones have reached a plateau of maturity for the moment and I can't see any "must have" features around the corner.
However there's a few potentially big features. LTE is one - it's not massively interesting right now but I think if/when network coverage improves it could be. NFC is another - right now it's software that needs to catch up, but after that more phones need to have NFC in them. And I'm sure there will be others that pop up in the near future.
What version of Android do you have running on your device and if it is the latest (Jelly Bean), how is the performance ?
The early 4.1 kept eating the battery but 4.2 is OK as long as I switch of wifi when out and about.
And I don't think UK carriers have any meaningful control about when Android OTA updates are pushed out?