A new iteration of Maxis' city-building and urban planning game SimCity is reportedly in the works and set for an official reveal at next week's Game Developers Conference (GDC) in San Francisco. Although still early in development and not expected to see the light of day until sometime in 2013, anticipation for the next SimCity is already building up after alleged concept art of the game turned up in online forums.

In a brief interview with German magazine GameStar, Maxis executive Lucy Bradshaw confirmed development of the game is underway, noting that work on Spore and The Sims had kept the company from revealing it sooner. She talked up the game's AI and features like updatable buildings and nonlinear road patterns. The game will also offer a multiplayer mode, allowing players to collaborate with other Mayors on commerce and other issues, while a global leaderboard shows ranking for things like economics or production of raw materials.

The upcoming release, simply named SimCity, will run on a new engine called Glassbox, which besides the improved graphics allows users to pan in close enough to read the signs on stores or zoom out for an overhead view. The game is reportedly only 30% done, so no screenshots are available yet. EA is set to present a session at GDC titled "Inside the GlassBox" that will highlight the technology behind "the next entry in one of its most beloved franchises", so perhaps they'll offer a glimpse at what to expect.

SimCity is being developed without series creator Will Wright leading the project but it will apparently remain faithful to the classic game formula. Maxis developed the first SimCity game in 1989. The last major release in the series was SimCity 4, which debuted on PC and Mac in 2004.

More concept art images for the next SimCity game are available in this thread at Neogaf.