Prince Harry is currently fifth in line for the throne. The line of succession is currently as follows:
No, they do not have any children.
Prince William married to Catherine Middleton in 29 April 2011
Prince William and Catherine were married at Westminister Abbey in England.
Prince William (who is the heir apparent and became the Duke of Cambridge when he married Catherine Middleton on 29 April 2011) and Prince Harry
Prince William and Princess Catherine plan to visit the US in July 2011.
At university
No, Prince William and Catherine chose to get married after a long relationship.
Catherine Middleton is the wife of Prince William.
Yes, Prince William did propose to Catherine Middleton. They were married in Westminister Abbey in England.
Prince William of Wales and Catherine Middleton will be married on 29 April, 2011 in Westminster Abbey in London.
He is known as William Prince of Wales. Therefore, the title will be transferred to her upon marriage.
Princess Catherine is a commoner, but I did no research on it. I just saw the headlines of the news when her and Prince William got married. It said Commoner Kate is marrying Prince William.