Surprisingly the game is still alive but so far according to CCP Games it's no longer receiving major client-side updates and is instead relegated to receiving only server-side hotfixes. This was announced back during Fanfest 2014. This is because Project Legion has been announced which looks like it will be everything that Dust was meant to be but couldn't be and it's coming for the PC. CCP has learned that they couldn't achieve what they wanted on the PS3 which by itself is an already aging console and the Sony QA process proved to be cumbersome for the indie company's taste despite not having to pay anything for uploading the updates.
As a result, Project Legion is in the works but it still needs to be greenlit by CEO Hilmar of CCP Games in order for it to be a full game. Much of the staff that worked on Dust has been moved over to Project Legion and it appears CCP has learned a tough lesson about hyping anything these days and is thus keeping it quiet about what's going on with Legion.
Dust in the meantime has received 3 hotfixes since Fanfest 2014 and it appears to finally become balanced where previously there was none. Missing militia gear has finally been added, matchmaking is finally being looked into by CCP using a new algorithm that CCP Rattati discussed in the forums, scouts have finally been overhauled, sidearms are being revisited for the next hotfix along with AV and dropships, etc. Overall, the game is finally starting to be fun in an incremental kind of way though it's still relatively frustrating for new players who have to grind to be competitive.
forums.dust514.com (looks for the stickies in General Discussion and Development Discussion Archives)