http://clanbase.ggl.com/news.php?nid=296685
For the uninitiated, perks are customisations that let you add certain skills to your in-game player, thus creating a custom class of soldier. Perks were a very popular part of Infinity Ward's award-winning hit game, Call of Duty 4.
Given their immense popularity Treyarch has decided to stick with them in Call of Duty: World at War.