The Joint Statistical Meetings are large annual statistical conferences. To quote their site,
"JSM (the Joint Statistical Meetings) is the largest gathering of
statisticians held in North America. It is held jointly with the
American Statistical Association, the International Biometric Society
(ENAR and WNAR), the Institute of Mathematical Statistics, the
Statistical Society of Canada, and the International Chinese
Statistical Association, and the International Indian Statistical
If you search "machine learning" in their 2011 program, you get 68 hits.
Two other annual conferences are the meeting of the Eastern North American Region (ENAR) of the International Biometric Society and the meeting of its western counterpart WNAR. Talks, posters, and sessions on machine learning have become a larger presence at these conferences over the last decade (you can find past years' programs in the links above -- the links to the actual programs weren't working for me this morning, however).