After watching some highlights of the guy, I am a little confused on how to beat him. He is a phenomenal counter puncher with excellent hand speed, is patient, is always backpedaling, has good defense, and is solid on the ground.
2 ways to look at it:
Although he is extremely skilled, he is boring and takes no risks.
He plays to his strengths and sets traps to not necessarily knock someone out, but to steadily hurt and defeat his opponents. His gameplan is very effective, which is part of the game in MMA and equates to him being a very, very formidable opponent for any fighter.
There's no obvious way to beat him because he really doesn't have any holes in his game. Nakamura tagged him a couple of times, so the only viable strategy I can really see is "be a little reckless and really fucking strong"
I see this as similar to the Kongo/Cro Cop fight. Lyoto is a fast counterstriker like Mirko, who looks for openings and picks his shots. To nullify that you have stay in his face, work the clinch, and in Sokoudjou's case take him down when possible.
Sokoudjou has to keep slow him down and disrupt his in and out striking. Keep him pressed up against the cage and work dirty boxing.