What does Yorkshire Building Society buying Egg mean for you?

Yorkshire building society is to buy Egg's £430 million mortgage book and £2.5 billion savings business from Citigroup, which has already sold the Egg cards business to Barclays.

More than half a million Britons with savings accounts and mortgages with Egg are set to become customers of Yorkshire Building Society by the end of the year as a result. So what does the deal mean for them and the Yorkshire members they are due to join?