Ideally there would only be one canvas with all objects and you could shape your own environment, change the time of day and decide what kind of weather there would be.
Sigh...
Would you pay for Limited Edition if it came with Forge+ and Theater+ for free, which would be optional DLC otherwise?
Let's say the business model is something like this.
Forge: Everything we've seen so far, magnets, how do they work, etc etc
Theater: Basically the same as Reach, maybe back to Halo 3-level post-processing when allowing online screens, though.
Forge+: Costs $10 (whatever that translates to in MSP; 1250?). Does not allow for importing custom models,
but pretty much everything else is possible--modifying a pre-existing set of setpieces/forge blocks/etc, possibly thousands of different structural items. You can share "Object Mods" with your own maps and create Object Mod Sets to share with others that would basically work like structure packs; in-engine you'd just be playing around with vertexes and the like of pre-existing Forge objects and saving them as new ones. 360 memory is basically the only limit. You can choose from a large variety of skyboxes, environments, and use the same object mod tech on terrain. All exists within the game engine but requires a bit of harddrive space.
Theatre+: Also costs $10 in spacebucks. Not a full-blown video editor or anything, but it allows you to snip clips and add basic fade effects and snip clips together with a maximum of 10 minute-long videos. Screenshots could possibly have some stupid function like Instragram filters. The important part here is that you could upload films to your fileshare, but Theatre+ allows you to download them (to your console or your PC) as an actual video file. Rendering could be free (thanks to you paying for Theatre+) or cost some amount of Spartan Points.
You could buy a Halo 4 Forge/Theatre Suite Plus combination for $15 (but in Microsoft Points).
