To clear stuff up:
Crysis Twitter: EA and Crytek run, useful for casual gamers to follow news/announcements on Crysis 2 not wanting to get too involved in forums and community stuff
Facebook: Similar to Crysis Twitter
Crymod: Don't think i need to explain
MyCrysis: Crytek run site, Crysis 2 community, discussion on all things Crysis 2, big official announcements etc.
Crytek.com: Company site, business and recruiting
MyCryENGINE: CryENGINE business site
Crytek Twitter: (NanoSmartCasual) official Crytek twitter run by me to give short frequent updates, answer questions directly and upload some cool stuff you don't get to see through the other sites like photos/videos in the studio, trip reports, news live from events etc.
Not everyone has Twitter, not everyone wants it, this is just another move by us to increase community communications and try to reach as many people with varying interests as possible. It's up to you to select which media channels you feel suit you and use those, we're simply trying to give you as many options as possible