Is it worth upgrading my iPhone 4 to an iPhone 5?

Pearsonally I'm stuck with a decision because I've had my iPhone for 23 months now and pearsonally when the iPhone 5 was announced I didn't really want to upgrade because it had no NFC and then I thought if I got it sim free it would be better so should I upgrade or wait to see what apple has to offer next year? Thanks for answering! ;)

Added (1). Also another reason why I wanted to upgrade is because I might getting it sim free- that means I can get 4G with the new EE 4G network also the reason why I didn't want to get it is because it supports nano-sim which I don't really like the idea of so should I upgrade or not? ;)

No
it will go on and on
be happy with what you have = happiness

Next year, they're probably gonna release an iPhone 5S which only adds a few new features (like 3).

Well, you should ask yourself, "Do I want an iPhone 5?". I mean, if you ask us, you'd get both answers: Yes and No. So it's better to ask yourself that. The iPhone 5 is better than the iPhone 4 in comparison by miles. But considering how there are much better phones out there as well (ones that do have NFC and doesn't use Nano Sim cards and can use 4G), is it all worth getting? Think about this.

Nobody knows what it is exacly like yet. Wait a few weeks to a month after it comes out. Read and watch some reviews on the internet. If it looks worthy of getting, then you should get it.
But it's all up to you!

You are right, there is no NFC which is a drawback. Compared to the iPhone 4 though the iPhone 5 has a larger screen and of course Siri. It is much better suited to games and videos and has the new Lightning dock connector which will be the Apple standard from now on (so any future accessories will not work as well on your existing iPhone).

EE probably won't have LTE working properly until the end of the year, so if you bought an iPhone 5 now you would not be able to use LTE straight away. You could buy the iPhone 5 sim free now and go without LTE for the time being, or wait until they have LTE up and running and get the iPhone 5 then (it might also be a bit cheaper in a couple of months).

If you iPhone 4 is getting a bit old now it is probably worth getting a new phone and even without NFC the iPhone 5 offers many benefits over the iPhone 4. You can compare contract prices for the iPhone 5 at Best Mobile Contracts:

http://www.best-mobile-contracts.co.uk/phones/Apple-iPhone-5.aspx

Hope that helps