IGN have recently interviewed Rockstar Leeds president Gordon Hall. The interview brings up a few more details we didn't know about, and IGN have also included 6 new screenshots.

• Graphical improvements over Liberty City Stories include higher poly-count models such as buildings, animated textures and more...
  
• A new system has been introduced for drawing objects in the distance.
  
• Jet ski racing will feature in both single and multiplayer modes.
  
• More than 100 songs will be featuring on the soundtrack
  
• The targeting system has been improved, especially when you're unarmed, "you can now perform grappling moves and throws, you can get on top of an opponent on the ground for ground domination, and more."
  

Links: IGN Interview, New Screens