McLachlan previously said, on more then one occasion, they (Lynch, Frost, cast, etc) had been talking about doing season four, and he said he was definitely in. Sherilyn Fenn said David enjoyed doing this season and that he would do another if the fans liked this season. I've read Showtime is pleased with how the show has gained a new demographic for them, and they also expect the show to do well when awards season comes around. Apparently, the live numbers for the show aren't the best, but it has been doing very well with streaming.

I'm not buying the most recent reports since the finale that there are no talks for another season - they already said there were before.

I think after awards season they look at script, budget, etc and start trying to line up another season. I don't see it coming out anytime soon though, I think it took them like 2-3 years to do this one, no?

Regardless, the mystery of "will they do another season" is just extra publicity anyway, so why bother to make it concrete so early.