A mission I'd like to see
I've played the original Splinter Cell and I'm just starting "Double Agent" on the PS2 (its all I have for the moment).
There are some environments that I think would be cool for a game. One of them is a pre-school.
It would be very tense to have terrorists take over a pre-School or High School in the middle of Arizona or something, as a means of ransoming off each of the children. Then Sam has to go in and neutralize a few of them, so they can be released, and kill the head of the organization and escape before the SWAT teams raid the building. There would be so much they could do with a concept like that.
The terrorists would use school bells to communicate the presence of Sam. No alert could be triggered. You have to kill most of the terrorists at once without one of them seeing, as they'll then turn against the children. Maybe - Sam could have the choice of risking the children's lives, or allowing the execution of a teacher to happen. The main terrorist is in the Principal's Office and thats where Sam has to take him out at. Sneaking down the halls, using a cafeteria for cover, tipping over bookcases over in the library as distractions, killing someone with a computer-monitor, throwing rulers or chalk to divert attention, hiding in teacher's rooms, etc.
He could also use contact one of the teacher's, students, or cafeteria members to assist him. Maybe, if Sam has to break open a vent in the lunch-room, a terrorist rushes in and the faculty all cover for him. Or, he tells a student to have people in his row to move slightly to the left, so he can get a clean shot.
I think it would be an awesome idea. Though, it might be controversial.