These odds are the results of running monte-carlo simulations of the Google Code Jam using rating as mean performance and volatility as the standard deviation. Coder performance almost certainly doesn't follow a standard normal distribution, so these odds are just for fun and should not be taken as having any meaning for your likelihood of advancing or winning money.
For coders who are not rated in TopCoder, I estimated their rating to be between the rated coders that placed on either side of them in their qualification set, and I assigned a volatility of 500.
Round 2 odds are here.