20100910 is out now. There are very few changes from 20100815, it’s only being released as a final test before 1.4 goes out the door next week. I expect 1.4 will be identical to 20100910.
Things have been progressing fairly slowly on the beta front, as most of my time has been spent on a somewhat secret project, which will be announced shortly after 1.4 is done, with alpha versions available to registered users at the same time.