While I cannot recommend a particular approach to estimating probabilities in soccer, I can provide a simulation framework for the coming World Cup tournament. The schedules were compiled from the FIFA and Wikipedia sites, and the structure is there to input team ratings, churn through a hastily modified log5 approach, and generate simulations in a Monte Carlo method.
Email or comment with advice on improvements, including team ratings and a formulaic approach to assess win/lose/draw probabilities given those ratings.
World Cup Simulator
Original Author- Erich
Original Release Date- 20100603