Update: April 25
The Alek Manassian attack in Toronto on April 23 is related to the Incel issue and the suspect said in a social media post that he was "inspired" by Rodger. Here is the explanation on Vox, by Zach Beauchamp. CNN has an even more disturbing account by Gianluca Mezzofiore here. The Toronto Star has a detailed report, which notes that there have been calls to ban a subreddit by a group of "incels", but which also questions the authenticity of Facbook posts attributed to Manassian.
Update: June 20
Sady Doyle in Medium writes about "The Deadly Incel Culture's Absurd Pop Culture Roots", here.