That's amazing milestone, congratulations Bitcointalk.
Where can you see those stats?
Any idea how many of them are active?
You can check them from Vod's website:
http://dev.martinlawrence.ca/bpip/Take 1,999,086 registered accounts, delete 1,082,472 accounts with no sign on for 90 days, no posts and no trust
and that leaves us with 916,614 active accounts.