What's the deal with ICC rankings?

[pinkfreud]

I'm at a loss to understand how India, even after winning the World Cup, is still 10 points behind Australia in ODI rankings? Oz has 129 points, while we have 119. That the World Cup is the most watched, most anticipated, and most competitive tournament in the history of cricket (no, please don't go on about the Ashes- no one cares about that except for England and Australia) doesn't seem to matter. Yet, a 4 match Test series between India and England in itself is enough to warrant some kind of change in Test rankings if England wins at least 2 (that's what I've read, please correct me if I'm wrong) of the 4 matches. As of now we have 125 points, while England has 117. I don't see the logic in England getting well over 8 points simply on the basis of winning half the matches in a 4 match Test series, and India not moving up the ODI ladder despite lifting the World Cup? I don't know how this ranking system works, so I'd be glad if someone has a far better understanding of this and can explain how it all adds up.