GILD/JNJ/BMY—It's not very surprising since there were question marks about Edurant's efficacy in comparison to Sustiva. I don't think Btripla will cannibalize Atripla sales to a great extent - there might be some usage in patients who have neuropsychiatric side effects with Atripla, but I don't envision much first line usage at all.
The other advantage of Btripla vs Atripla: Edurant is Pregnancy Category B (no known risk), while Sustiva is Pregnancy Category D (empirical evidence of fetal risk).