In reply to Matt.

@Matt Two million sites would be quite a lot for 3.7, actually.

Here's the thing about the question "how many websites are there?": It all depends on what you consider a website.

For estimates that consider the number of domains and things, then you'll generally see an answer in the 1-2 billion range. But then this includes domains that never get anything more than a landing page on them. Not exactly what I would consider to be an active website, or one that would run a CMS or anything of the sort.

A more realistic estimate of what you and I would probably consider to be an active website would be in the 400 million-ish range. Of those, let's say about a third are estimated to be running WordPress. According to the stats page on w.org, 3.7 is running on 0.137% of those. Even with the most optimistic math, that's only 200k sites. Even that third number is a bit suspect, and the number from Builtwith says 30k. I suspect the real number to be in the 50k-100k range, at most.

The 2 million reference cited on that make page is the number running 3.7 - 4.6 total, not just 3.7 alone. So, when discussing this proposal, consider that the initial starting set of bumping 3.7 to 3.8 would be for maybe 100k sites, maximum. It's a very small starting point to work from, not a hugely major undertaking.