I think that the epidemic of the last decade is that most new games of classic FPS series from the 90s get so different and unrelated with past games of their franchises.
And it happens mostly because of "Reboot" games.
Reboot usually means: something completely different that will dissapoint fans of the original.
It happened with Wolfenstein (2009),all Turok games from Evolution and after,Perfect Dark Zero,the many incarnations of Goldeneye from both EA and Activision...
These games made fans of the previous games of the series alienated and dissapointed,because the games might had the same name,but played in very different way.
Can't they just do what Ninendo does with their series ?
In a Mario game you know you will be Mario,you will jump lot's of times,collect stars and you will fight goombas.
What that means ?
Same protagonist/playable character,same focus on gameplay,same mechanics,and familiar enemies/persons.
You can write a new story,add new characters,add some new gameplay mechanics,but for the goodness of all,don't change the basic fetaures that made a series what it is!
And that's why I have hopes for Duke Nukem Forever.
If there is one thing people (IGN) are complaining about it is that it feels like a 90s game (Duke Nukem 3d)and not like Halo or Call of Duty.
Well it better feel like that!
Why some stupid folks say that it's a bad thing if a game keeps the things that make the series what they are in first place ?