I would love to see a Phantasmagoria 3! Especially if it was more like Roberta's Phantasmagoria 1.
My guess is that it will never happen, but I don't completely understand why not. Phantasmagoria was a huge hit for us. It was killed by the acquisition of Sierra. It's a long story, the short version of which is that the company who acquired us had people in their sales organization who disagreed with the content in Phantasmagoria on religious grounds. Basically, they didn't push it, and without a sales/marketing effort the game stopped selling prematurely.
I've thought about doing a Kickstarter to do another Phantasmagoria style game, or simply calling Activision (or, whoever owns the rights these days) to ask if they'd fund the game .. or, simply funding it ourselves. But … at this point Roberta and I are happily retired. We miss doing games, but we don't miss having to stay put for years to build a game. We like travel too much!