If he moved to 205 he would be a force to be reckoned with.
I agree. While I think he was certainly more than effective at heavyweight for many years, the truth is a new wave of "true heavyweights" have entered into MMA that are pushing the limits of the 265lbs mark and its muscle rather than fat unlike the previous era Fedor was dominating. To make matters more complex these new athletes at HW also have a much deeper and diverse skill set than previously seen in the division. I think before while Fedor may have been outmatched in size/athleticism he always had a much more complete MMA game which allowed his undersized disadavantage to be covered up, but now its just too hard to make up that much of a disadvantage now because the HW's of today are more complete mixed martial artists.
Fedor at 205lbs could compete with anyone in my mind, and in all the recent videos we've seen he's looking slimmer than ever, and makes one wonder why the reluctance to move down? I personally believe he's one of the few guys that might actually offer a challenge to Jon Jones because he'd have a ground game to truly threaten Jones and striking power to force Jones to respect him standing.
All in all, I think Hendersons best chance is a decision victory via takedowns and grinding, a la Jon Fitch (what I like to call "winning ugly"). For Fedor, I'm seeing either TKO or submission off his back after being taken down.
Like many others I'd like to see Fedor win simply because the sport needs him to stick around, while Henderson can afford a loss (losing to Fedor wouldnt hurt his rep at all).
It'll definitely be exciting none the less since I do think Henderson does possess the tools to beat Fedor, and for Fedor it'll be one of the first fights in a few years he's the larger man, and athleticism/size wont be a disadvantage.