The current British royal family
Seated from left: Prince Charles, the Prince of Wales (the heir-apparent), the Queen and her husband, Prince Philip, the Duke of Edinburgh.
Standing from left: Prince Andrew, the Duke of York (fourth in line of succession after Prince Harry), Princess Anne, the Princess Royal (second child of the Queen) and Prince Edward, the Earl of Wessex (youngest child in the family and his father's successor to the dukedom of Edinburgh)
For the past months, royalists frequently debated the issue whether it's time to change the law of succession of the British monarchy. This topic became the favorite subject again when the Queen and the Duke of Edinburgh paid a recent visit to one of the monarchy's largest dominions, Australia (other British dominions are Canada and New Zealand).
Several news noted that it would be an attracting point to the republicans to make some changes on the archaic law of succession to send a message to the world that the monarchy is finally breathing the air of change.
The present law of succession guarantees only protestant heirs and still following a primogeniture or male-preference succession. In Europe, only Luxembourg, Liechtenstein, Monaco, Great Britain and Spain have yet to decide whether to embrace the succession changes. Other European royal houses already established an equal law of succession: Belgium, Denmark, Norway, Sweden and the Netherlands.
Should Britain decide to make some changes on its succession rules, children of the current British Queen would not be under this rule, so Princess Anne still would not leapfrog her younger brothers, Prince Andrew and Prince Edward, in the line of succession. The possible changes would take effect on the future royal children. If William's eldest child is a girl, under equal succession, she would automatically become the heir-apparent even if she will have younger brothers.
Maybe it's time for the British monarchy to make good use of their views to embrace modern changes, afterall, the Queen finally gave her permission for Prince William to marry a non-aristocratic woman which was an inconceivable idea in the past.
If the royal court is slowly accepting commoners into their fold, there's no reason why they couldn't implement changes on the law of succession, including the possibility of allowing royal family members to marry Roman Catholics (as of this writing, the Act of Settlement never allows royals to take a Roman Catholic spouse, if they do, they would be automatically remove from the line of succession).
The world knows females too are great rulers and Britain knew it more than any other countries as its history witnessed the reigns of two female monarchs in glory and prosperity--->The reigns of the two Elizabeths: Elizabeth I called the Great and currently, Elizabeth II.
Update on the Change of Constitution as of October 28, 2011:
Reuters-Australia reported that the 16 Ministers from the Commonwealth Realms which recognized Queen Elizabeth II as its Head of State, finally agreed to the change of succession law proposed by British Prime Minister, David Cameron, who called the ancient law "outdated".
The change includes lifting the ban for British royal family members to marry a Roman Catholic. Under the former Act of Settlement which governed the law of succession since the reign of Queen Anne, no British royal family members should marry a Catholic, doing so would automatically remove them from the line of succession, but now in the new law, this restriction would no longer exist. A group will now be set up to coordinate the necessary legislation for the changes.