I highly doubt it's a name change. It was noted that there were five major projects being worked on by CCP, one unannounced. (And since that statement, one of them, WoD, is dead.) EVE Legion is likely that "fifth project" people were curious about a few months ago.

Ok, I agree with recent posters, EVE:Legion is probably the mystery game in development.

New theory: it's going to be like an RTS where players control drones and try to take over planetary or space facilities.

It will be fully integrated with the EVE universe. It will be an app you can play on mobile devices.

BAM! AI for Dust PVE solved

It's probably just the name of their next EVE expansion.

When the first cloned soldiers were created, they used the implants that were inside the unused bodies of 'Sleepers", an extinct race who left clones behind, idle. The implant put inside these first few immortal soldiers was part of another person, they had another person inside their head. This meant that they would hear things, and one thing that always rang in their ears was 'Dust 514', which drove some of them crazy. These problems were to disappear when they could figure out how to make the technology themselves and no longer needed to harvest Sleeper clones. What Dust 514 meant however, is lost to the world, as the Sleepers are gone.... but the Jove... the Jove might know

well it wouldn't make sense to hype up the reveal of what 514 means then just change the name