According to PlayThree.net, the CVG GTA special is out and claims that the Xbox 360-only DLC for GTA IV could contain an area as significant as Vice City or San Andreas.
From the magazine:
“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. Yes, Rockstar is clearly hinting at new downloadable cities; and the chances of them being London, Vice City or SA again are slim to none. So that’s new as in brand new. GTA IV’s Liberty City is the beginning. Think about that and be excited.”
Blimey. Not long to go now!`