Just saw this news about Pownce annoucing their public API, set to be released in September: http://mashable.com/2007/07/25/pownce-public-api/
And here was my prediction on July 11th for my Precog idea for a Pownce Facebook plug-in:
Prediction: Within the next 2 months, Pownce will open its API and allow users to develop 3rd party apps. This is based on the success Digg is having with its open API and to better compete with similar offerings like Twitter and Jaiku, both of which have open APIs.
Likelihood (1 – 10): 9 (very likely)