Ya, they are playing it very conservative. Maybe they don't want to appear to jump the gun. They're wording suggests that no way this can go to Winter Storm Warning criteria...we'll see.
The north and northwest burbs should easily get 4-5 inches, if they haven't already! The southwest side by me would need several more hours of this to reach the low end of that. But it is snowing at it's hardest of the night right now!