Not knowing the current ownership/rights around Fire Walk With Me, I'm pretty sure that if one man wants it released it will be. That one man is David Lynch, who has been historically opposed to the idea of a "directors" or "extended" cut to any of his films.
Peaks is near and dear to his heart and my sense from reading interviews with the man is that FWWM – and Peaks – is done.
The next best thing isn't that bad though – we have the film, and if you are really curious you can find the final shooting script (which of course has all the cut scenes) online. It helps fill in the gaps from series to film, and it's filled with some of the Peaksian eccentric characters that are sorely missed in the film.
I made the mistake of reading the script before watching the movie way back when it was released so I was very disappointed at some of the omissions – don't make the same mistake I did, watch the movie first (after you watch the series, of course) and then read the script.