I went from 5.39 L/100km in 2009 to 5.23 L/100km in 2010.
Not a huge difference, only 3%.
But looking at the 2nd half of 2010 (I joined ecomodder in July), I'm down to 5.00 L/100km or 47mpg - by coincidence, that's actually the car's rated fuel consumption. That's 7% less, despite some technical issues.
I'm actually getting nearly 47mpg on winter tyres in the cold through more changes in driving behaviour, so I wonder what mpg summer will bring.