I'm 90% sure that 15M of those new users are just Jon Skeet clones that upvote him!

But in all seriousness, stackexchange have completely stolen the parade from all other community driven Q&A sites.

Joel was correct when he withdraw support for customer hosted Stack sites, and went through the incubation process.

Stackoverflow has totally wiped out all of the other failing programming websites, and the community is a great one to be apart of. (I hated those sites that would obfuscate all the answers and try and get you to pay to sign up, while cloaking everything on Google).

Congrats.