There must be something in what they're saying though, i mean if tomorrow they announced new maps with plots 4x4 bigger is available, then it potentially sells more copies of the game, because some people refused to buy it saying its too small, existing owners play it more and that opens up the possibility of DLC sales to returning customers, and if existing owners systems cant handle it, because its super intensive
then those people dont have to play it, they've not lost anything its not like half of the 10 regions would have been unplayable if say they'd done this say 1, meaning they're getting half the content.
Short of holding it back for SimCity 2015 or something, im not sure what the point would be if its a really simple job. I dont believe its all that complicated, although i could believe their engine perhaps starts doing stuff very wrong when its routing agents are calculating the best route when the map becomes considerably bigger. They might be able to fix it, or it might require a significant rebuild which makes it impractical to patch it into the existing game, but its fine for a new build.
I certainly dont want to make excuses for them, I played the game for about 10 days and havent touched it since (so first 14 days from launch, havent played since) but i believe there must be something legitimate there, simply because they could claw back some public opinion by doing it, even if they charged £5.99 for it as a map/region pack DLC.
They've said they'd remove the online requirement, something they claimed was too complex for most computers to manage (!!) which must surely require them to spend time on something which wont make much difference to potential new customers or existing ones. Larger maps would, yet they havent.
Still waiting for modding support, you know, like they promised.