Oh, I see. Some people here misinterpreted what I wrote to suggest that Python isn't widely used. Clearly that's not what I meant.
I just dislike how melling basically pulled a number out of his ass, and then used it as "evidence" to back up his claims. I wouldn't even consider it a low-quality estimate, since he doesn't even try to justify or explain how that number was obtained.
In this case, "tens of thousands" could very well really be "hundreds of thousands". It could be significantly less, too. Regardless, it's purely speculative. Using such made up numbers makes his argument weaker than perhaps not using any such value at all.
No, I picked what I thought would be a lower bound. Do you think it will only be a few hundred or few thousand over 6 years? Python is an extremely popular language.
I've worked in industry for 20 years. People take the same version of the interpreter, or start with existing scripts, to create new scripts. Even if there's a one rev difference, people often don't bother to upgrade. There will probably be hundreds of thousands, if not millions of Python 2.x scripts written over the next 6 years. Many will be small, of course, but it's code that will have to be checked against 3.x at some point. I threw out the conservative number because I thought it would be obvious to most people that given Python's popularity, a lot of new 2.x code will be written.
Obviously, if people were moving more quickly there wouldn't be a need to push out 2.7 support until 2020.
In fact there'd be "tens of thousands" websites made with Python alone (Django et al), so the number of apps in total will be much higher.
Heck, people doing scientific Python are more than 10.000, and they write more than one new apps for their research every year.