SUPERMAN UNLEASHED is one Superman reboot pitch
But we know nothing about it, other than it's listed on the "in development" page at the Legendary Pictures official website (though the site has to be hacked to be found) and that it's being billed as a sequel to SUPERMAN RETURNS. 
Ramping up the action of its esteemed predecessor, the sequel to Superman Returns promises to raise the stakes and take the audience to heights of action that no other superhero movie can achieve.We don't know who pitched it (maybe Singer?) or what it's about but it's just one of what you would think are many Superman related project pitches turned into the studio over the past six months since the studio confirmed they were inviting scripts from anyone with a good idea for either reboots or sequels. Wish I could be a fly on the wall at the WB offices, hearing conversations about the pro's and con's of each individual pitch. source - /film and their computer hacker friends.