I've removed the https to make the link work.
No SSL for Top 3 search engine on bitcointalk ? 
OK then, edited previous post
So looking at http://loyce.club/archive/members, we shall be able to get accounts that were registered at a given period of time but are still active or were at least active from the time LoyceV started archiving posts.
My data started less than 7 months ago. I didn't even think about using this, so thanks 
There's one flaw though: this only includes users who made a post, not the accounts that only changed their password to activate later. I can scrape all 2011 profiles if iasenko wants it (it'll take a day).