I've posted M4-beta here. It's made from r721165: http://people.apache.org/~rhs/qpid-incubating-M4-beta/
One thing I noticed is that the cpp dist tarball has jumped up from 18MB to 131MB. As far as I can tell this is all from stuff under docs/api/html, so it shouldn't impede testing, but might be worth looking into for the next RC.
--Rafael
