I have often speculated on how the country's history would have been rewritten if Harold had repelled the Norman invaders - whether the Normans would just have kept trying; whether another type of conqueror would have arrived; what cultual differences might there have been. Can anyone recommend some reading matter?

Was't there a series of "What If?" programmes on a year or two back? Did one of them cover this?

There is an article in the 'What If' books, the second book I think. I haven't got the book here at work but the author explored the idea of Anglo-Saxon society that looked more to Scandinavia rather than France. The language would possibly be more akin to Dutch.
However,I would need to re-read the article to be sure.
Jodee