Good news! In a post on the official SimCity blog, Maxis have confirmed that an offline mode is on its way. The new mode is currently in closed beta testing, with promises that it'll roll out to everyone in Update 10. Maxis first mentioned they were working on the mode last October, although RPS threw sand on the initial claims that offline mode was prohibitively difficult just days after the game was out.
The post on the official site outlines some of the details for the new offline mode. First of all, you'll now be able to manually save your city, meaning you can destroy it and explore your creativity without being trapped by your own decisions:
In Update 10, you can still play solo in Regions on your own, or in Multiplayer with people from around the world. What’s new is the Single Player Mode, which allows you to play the game Offline by yourself. And because your saved games in this mode are stored locally, you can save and load to your heart’s content. Our team will be delivering a follow-up blog that will outline the full details in the near future so stay tuned.
The mode will also make it easier for modders to change the game without impacting on the sanctity of the multiplayer experience:
Bringing the game Offline means big things for our wonderful community of Modders. They can now make modifications to the game and its components without compromising the integrity of the Online game. Modding is a big part of our studio’s legacy and we’re excited to see what you guys create.
Maxis spoke about modding last week, outlining a set of guidelines for people wanting to mess with the city builder's guts. In brief: don't break multiplayer; don't breach copyright; be family friendly; the EULA and terms of service still applies; EA retains the right to crush you; EA has the right to promote, distribute and sell your work; but you can't sell it yourself. These are (mostly) typical of the rules around modding.
The offline mode is a real boon to the community though. If you've got no internet connection or just a shaky one, this is the difference between being able to play the game and not. The only downside seems to be that your existing cities can't be transitioned from online to offline saves; or at least, there's no mention of it in the initial post. Maxis are promising more detail should follow in the following days.
EA stated again and again after the game's release that taking the game offline would require "significant engineering work" because so much of its simulation was happening in the cloud. That engineering work has presumably been taking place over the last few months, although as linked above, a Maxis insider told us it wouldn't be so difficult, and some quickly created mods seemed to back that up.
Anyway. This is good news.