To trade in for new or not?

Opinions appreciate:

I have a UK i10 Style, red solid paint, bought under scrapage scheme (so paid circa £6500 in 2010).

I can get a new car, same specs, by training in mine for around £4900, and paying £129 per month for 3 years, £4644 - so that's 0% finance.

So is this worth doing?
Is it more economical to run mine into the ground?
Or wait for new models - I heard out around Nov / Dec?

Mine is faultless, bar a few scratches, and low mileage, around 14k.

So deal or no deal???!!!