For the longest time there has been numerous hints from Crytek that Crysis will be a trilogy. The latest hinting occurred on November 15th. Now, thanks to a tip from francis_23, we have GameStar's report from Lichtblick 4D Meet & Greet where Lead Animator & Animation Manager Steven Bender revealed the first small details on Crytek's plans for Crysis 2.

the second part is to resume not only history around Koreans and Aliens

According to him, the developer's attention will be even more focused on graphics. There will be numerous improvements regarding textures (especially facial textures) and 3D-animations. Their ambitious aim is to push the game's visuals to an advanced level, that could be considered near photorealistic movie quality.

GameStar report (Google-translated)
GameStar report (German)