The preview was a bit frustrating, contents of 2 page only and the reporters were given the same 15-minutes demo.
Here are the summary as quoted from Matt's Blog
Originally Posted by GamesMaster
* Drawing a gun will see crowds scatter
* Grass grows through the concrete paving stones
* You're not going to feel good 'accidentally' ruuning over pedestrians anymore
* Niko wears vinyl shoes
* Mobile phone allows you to co-ordinate with other characters to tackle problems