I don't think Strogov is dead...and I don't think that assassin would be that officer...but I think the game is not so short if you play it on hardest and you get max. ratings...
...and 7 new missions are coming! there are a lot of pics and a video about it:
http://www.dtf.ru/project/gallery.php?id=995
(low quality)
http://smersh.games.1c.ru/?action=videos (high quality)
"Смерть шпионам: Момент истины" (Death to Spies: The Moment of Truth)