Did they actually refresh the art assets for HL:Source? I would love to play it again if it's been reworked some.
Unfortunately they're not going to be redoing some or most (possibly all) of the art assets. I don't remember the official details about that part so I could be wrong. The main differences between the original and HL:Source that will be noticable are some of the effects the new engine brings to the table. New water effects, physics, lighting, and things like that. http://www.hl2fallout.com/screenshots/albums/album01/HL1Source_Ithy.jpg
Hopefully there will be a fan project which does spruce up everything. You'd think Valve would take this opportunity to bring HL up to current graphic standards... But then again they've got plenty to do right now.