Crysis 2 is finally out! I remember I've pre-ordered the game on 05/12/2010 when the release date was set to September, and after almost a year later the game sees the day light... and without DirectX 11 support! Sad, but true.
But that isn't the only missing thing, the game also lacks multi-GPU support and flickers like hell until you disable CrossfireX. But you can still enjoy better performance of your CrossfireX setup without the screen flickering with the help of an old trick, you have 2 options:
1- If you own a retail Crysis 2 copy, just rename Crysis2.exe to Bioshock.exe in game directory.
2- If you bought Crysis 2 on Steam or Impulse and you're using Windows Vista or better, create a profile for the game using Crysis2.exe as profile executable and at Tweaks tab set Bioshock.exe as CrossfireX compatibility profile (see screenshot below for details)
Doing so CrossfireX performance gains won't be awesome but you will still have a small performance increase without the flickering issue.
Screenshot credits: iowns at Adrenaline.com.br Forum.