According to
Videogaming247
the Computer and Video Games magazine GTA IV special is out and has some pretty juicy details about downloadable content that could be coming for the 360 version of the game. Not content with just new modes or fancy cars, they are talking about entire cities. Here’s a quote:
"Of course, to call games as vastly ambitious as Vice City or San Andreas mere ‘expansion packs’ seems childish, but nevertheless, the downloadable content (DLC) coming for the Xbox 360 version of IV has repositioned those games in just this way.
DLC so far has meant the odd new car, jumper of bit of horse armour, but GTA IV is set to completely redefine the idea with expansions that are to GTA IV what Vice City or San Andreas were GTA III.”