First a part history of the car.
2002 Polo 1.4tdi.pd
Cambelt and tensioner changed @ 4 years and 10,000 miles, job done by main dealer.

Car now 8 years old and 14,000 miles on the clock due for a new cambelt so I go looking for some quotes.

VW Independent garage advises me to replace the water pump at the same time as the cambelt because the pulley/impellers on the pump sometimes break up causing cambelt failure. (there are some articles on this on the web) quote £330 using VW cambelt tensioner and water pump.
The water pump I have found out cost £40 so the cambelt change itself cost £290.

I then went to the main dealers expecting the quote to be about £100 more and I got a pleasant surprise they wanted £299 for a cambelt change only (apparently I should have had a cambelt change special offer voucher through the post ) . I though to myself only £9 more than the independent for the cambelt change I will let the main dealer do it. I then asked him to add on a water pump replacement (£40 extra) and he said what on earth for. I told him I had heard of the pumps breaking up he said dont believe all you read, we have no evidence to support this, the pump will be checked when they do the cambelt change if it is faulty we will let you know.. As an employee of the VW dealer you would have thought he would have said yes play safe have the water pump replaced but here he is telling me not to waste £40.

The point is what is the trueth about these water pumps is there some scaremongering going on