It was Brentorboxer that hit the 100,000 waymark posted and approved. Although the system showed at one point that I had the 100,000th waymark she had a waymark or several in the queue that were not approved once approved the "100,000th Approved Waymark" kept changing until she was recognized as hitting the milestone.
The last time I ran my stats page the target date was Sept 5th.
The 500,000th waymark should be about October 28, 2013. :)
KE