Well these are the official rankings from the beginning of the season, they are determined by how a player performed the previous two seasons. The only time they officially change is at the end of a season, so after the World Championship. That's why White and Hunter are still so high.
The provisional rankings before the start of the WC were like this:
1 Stephen Hendry
2 John Higgins
3 Ken Doherty
4 Ronnie O'Sullivan
5 Shaun Murphy
6 Stephen Maguire
7 Mark Williams
8 Stephen Lee
9 Steve Davis
10 Barry Hawkins
O'Sullivan can get the number one spot back, but then he has to get far in this WC, he may even have to win it, I'm not sure about that. White is out the top 32, don't know where Hunter will end up.