In regards to the weather on the planet will it be persistent and move realistitically? For example if there’s a thunderstorm nearby will it move into the area or will the weather remain in a static location? 

The weather patterns are unique to each area. So for example it could be snowing in the artic region and when you enter the moderate region, it could be raining or storming there. Given the realistic time of day effects, all the weather fx have different attributes that make the world more dynamic.

There’s some difference in the power required for the PC version versus the Xbox 360. Will there be a significant difference in the graphics for the two platforms?

We designed and developed first on the PC. For any other console platform we decided on after, the game would be scaled to match. We’re not doing it the other way around like those other guys because we are, first and foremost, PC game developers and are dedicated to the platform.