It seems that we're now fully into the next wave of kaiju films, starting with Pacific Rim and Godzilla 2014 (possibly Monsters as well, if you count that one). I can think of a handful more that have been announced, but I'm not sure that they're all going to be successful.
Disclaimer: My predictions are almost always wrong. Take them with a grain of salt.
1. Godzilla 2 (2018)
Little is known about the film except that:
-Gareth Edwards will return to direct, but not until his Star Wars spin-off film has been released.
-Mothra, Rodan, and King Ghidorah have been confirmed at this year's San Diego Comic-Con by Edwards, and minutes then later by Legendary via Twitter.http://www.ign.com/articles/2014/07/26/sdcc-2014-who-are-the-monsters-of-godzilla-2
I was fine with the restrained approach in the first movie, but for Pete's sake, don't do it with this one. You can't have that many big name kaiju in one film and then take a restrained approach again.
My prediction: Financially, I think it will do well. Legendary will probably hype the hell out of it and convince a ton of butts to sit in front of the big screen. Although I want this movie to be really good, I'm skeptical that Legendary can deliver. US film studios have never dealt with other Toho monsters before, and I'm worried that Legendary will make "necessary" alterations to the beasts. Also, something about this movie says, "Wrath of the Titans all over again."
2. Monsters: Dark Continent (2014)
So they've ditched the romantic subplot for a what appears to be The Kaiju Locker... I'm down with that, as long as they provide more monster madness this time around. Also, Gareth Edwards is not directing this one, but he is an executive producer or something like that.
My prediction: I think this one will fade into obscurity, not because of its quality, but because of lack of attention.
Rumor mill: They're planning on turning this into a full-blown franchise. I'll believe it when I see it.
3. Gamera (2015, supposedly)http://www.dreadcentral.com/news/52226/new-gamera-movie-coming-in-2015/
Supposedly Kadokawa Shoten has announced a new Gamera movie. I don't know the particulars, but they shut down their film division not long after declaring Gamera the Brave a financial flop. My guess is that they've licensed the character out to another studio. Word is that Shigenori Takatera is helming this project. The last news I heard was that character designs are coming soon.
My prediction: It will be canned or turn out to be a hoax. I've also heard that they want to take a realistic approach this time around, which will likely not work. Part of what I love about Gamera movies is that they laugh in the face of plausibility. Take that away and you'll just have another run-of-the-mill monster flick.
4. Pacific Rim 2 (2017)http://www.imdb.com/title/tt2557478/
I don't know that there's much to say. Give me robots punching monsters and a little humor and melodrama and the sequel should be fine. It's a little hard to screw that up.
Prediction: I think it'll do well, but I have a feeling it'll succumb to sophomore slump, or that Legendary will pull a Matrix and basically make 2 and 3 one complete storyline split between two movies. Please don't do that.
5. Skull Island [King Kong reboot] (2016)http://www.imdb.com/title/tt3731562/
From what IMDb says, this is an origin story for Kong, and I don't think this will be connected to Peter Jackson's King Kong. Also, the company working on this is Legendary, collaborating with Universal. Are there crossover implications here? I kind of doubt it, what with Godzilla's height and all, but I'd be down for a rematch.
My prediction: I actually don't have one. I'll hold off until I see a trailer.
Other rumored movies:
Godzilla vs. Hedorah 2- Supposedly Toho has given Yoshimitsu Banno the go-ahead to do a non-canon sequel to Godzilla vs. Hedorah, following the projected success of Godzilla 2014 (for which Banno was an executive producer, if I'm not mistaken). Word also has it that a new monster called Midora will join Godzilla in the destruction of the smog monster this time around. Again, I'm skeptical. I'm pretty sure this one is just another forum-generated hoax from one of the Godzilla fan sites.