Spotted this video on YouTube. Mauricio "Shogun" Rua tells a group of fans that it looks like he will fight Quinton "Rampage" Jackson in December. Do not take this as set in stone. Shogun is not exactly the best source for upcoming fights. However, with the sudden media blitz by Rampage this week, it seems the UFC wants to get him back into the ring as soon as possible. A December return at the end of the year PPV would be a perfect opportunity.
As for Shogun, I have heard for weeks now that he will not be in the ring until December at the earliest. A fight between them makes sense. Both lost to UFC Light Heavyweight Champion Forrest Griffin and they have a history from Pride with Shogun winning the first match-up. Putting them in the ring together would be in effect an elimination bout to see who deserves a shot for the title, which presumably will be on the line that night with the winner of Liddell/Evans facing Forrest Griffin.