From the Noble Analysts conference held today in Houston, TX ...
Page 14 of the pdf entitled "Entire Presentation" downloadable at the link below gives the best info Noble have released to date.
They are saying a 25% chance of the Aphrodite prospect holding 9 trillion CF, rising to a 75% chance of a reserve of 3 trillion CF, and they are giving an overall prospect of geological success of 60%.
http://investors.nobleenergyinc.com/