I'd like to see this in 2014. The Floyd that fought Sat wouldn't really hurt Kell and Kell is infinitely faster than RG, as well as being a much better boxer.
It would be a top 10 WW, bordering on top 5, and would warm up the UK audience for a potential Khan money making showdown the next year. I wouldn't be absolutely blown out of my chair if it happened. Better to take on a mid-lower top 10 WW than a mid-lower top 10 JWW.
I like Brook, but he has fought absolutely no one to a) have any idea how he would cope with a world class fighter b) to even be mentioned in the same conversation as a Floyd fight.
Look at the styles he would fair a lot better then rg he got power in both hands and his skill set is very good finds the openings well and can box brawl the whole package.