"The catch is that Epic requires a 5 percent royalty fee after the resulting product -- whether it's a game or an animated film -- brings in $3,000 per quarter. Previously, developers were required to shell out $19 per month to use the highly-popular game engine."
I would like to say that this seems a bit miss-leading the way it is written, when Unreal Engine 4 was a $20/month subscription they still charged a royalty when something was produced and revenue was generated. The royalty is not relevant to the change in monthly cost to free, but the way this was phrased makes it sound like it was not there before.
We have reached the 10 year mark. Valve can no longer make Half life 3. The HL pedastal is too high now and expectations have reached Nukem proportions. HL3 would have to be the greatest game of all time in order to avoid going down in history as "not as good as HL2"