It appears Star Wars: Battlefront III is not the only entry in the series LucasArts cancelled before even making an official announcement. Siliconera has posted a batch of concept artwork for Star Wars: Battlefront Online, a canceled title that was rumored to be in development for Xbox 360 and PlayStation 3.
Resident Evil: Operation Raccoon City developer Slant Six Games was reportedly working on Battlefront Online in 2010 before its cancellation. It is not clear what stage of development Battlefront Online was in when LucasArts decided to scuttle the project, or why the company chose to not pursue it further.
The concept art for Battlefront Online shows off familiar Star Wars environments, characters, weapons, and vehicles. The images are available below and at Siliconera.