I am really interested in this camera, mostly for travel and street work. I almost pulled the trigger on the X100 a few months back. I glad I waited. What I think I was most happy about was the High Speed Auto Focus and Quick Response as well as increased ISO coverage. So really this update is all about speed.

Auto-switching between phase detection and contrast AF,
New Intelligent Hybrid AF brings your scene into focus in only 0.08 seconds*

Fuji claims cleaner high ISOs by one stop. The X100S will let you set AUTO ISO to grab as high as ISO 6,400, while the X100 could be set to go as high as ISO 3,200 in AUTO ISO. That should be good considering the speed of the f/2 lens.

The Fuji Guys show you all the bells, whistles and features of this camera