So I ran this query which shows the number of registered users over time and it looks like the rate of increase has actually slacked off some.
The Y axis is the number of users and the X is the number of months.
Some more statistics,
7.4% of users have over 200 rep
1.03% of users have over 2000 rep
0.77% of users have over 3000 rep
The top 10 most active users wrote 890 questions and 1684 answers for 26% of the questions26% of the questions and 20% of the answers20% of the answers.
In this month so far there has been approximately 6400 votes, 21%17% of that has come from the top 4 voters2 voters this month and the top 4 have contributed 21% of the votes.
The point I am trying to make with those statistics is that a great deal of the activity is being driven by a very small amount of users. So I don't think that there is a real uptick in usage from newer users.
As for why you are seeing a lot of activity from new users on that question is because it hit the Hot Questions and it's one of those questions where everyone has an opinion.