Call of Duty is and always will be run and gun. You might get the odd stealth level in each title but it will be nothing like splinter cell.
You can have a normal crossbow for stealth kills, or one with explosive tips for when you need to 'go loud'
Anyone who wants more info buy this months Playstation Official Magazine. They have played 3 of the levels already, and Treyarch confirmed that its set over 'decades' of the Cold War.