I wouldn't call Frank Mir an up and comer. I think there is opportunity for some great fights for Fedor in the UFC. Lesnar who already has been mentioned, Mir, Carwin, Velasquez, even Dos Santos and another shot for Big Nog. Rogers was a decent opponent for Fedor, but who is left outside the UFC that is worth fighting. Barnett and maybe Overeem, that's about it. Face it, the HW division on a global scale is pretty weak.
Since Pride's demise, UFC is THE organization for MMA whether you like the way they run business or not. The UFC doesn't have to cross promote anything. Cross promotion may work for an up start company, but not for a company with the size and global reach and appeal that the UFC has. Fedor could have easily signed a 4 fight contract with the UFC, won all 4 fights and left, but when he decided to go to strikeforce it felt like he was trying to protect his legacy more than anything else. He knows if he loses a fight his stock plumits.
My question is, if(when)Strikeforce goes under, where is Fedor going to go then, back to Japan? The next Strikeforce card is on December 5, and so far Fedor is not on it. It'll be interesting to see the numbers after that one.