The average broadband speed across the UK is 6.2Mbit, where as the average advertised speed is 13.8Mbit, so most people are getting less than half the speed they are paying for.
However, in some other European countries the average speed people are getting is over 16Mbits; in Germany and in Holland they are getting over 23Mbits. Luckily Virgin Media have been rolling out 100Mbit around the UK since October 2010 with an expected completion of around the middle of 2012, so if you can get the 100Mbit service you can help bring up the average UK internet speed, especially with results like this:
Heres hoping that once the rollout has completed that the speeds will stay around the same levels!