Let's first make sure we're all on the same page. Ward is one division above GGG. What @imp and @Ron Swanson talked about in another thread that they want to see is the best middleweight in the world go up and fight the best guy in the super middleweight division because there is no one else that can give GGG a good fight in his division, the division below and the division above. Be up front about it: that's a heck of a compliment, gentlemen.
I don't necessarily agree with all of it. I think a Floyd-GGG fight would be tremendous. From a styles point of view, if Lara moved up I also wouldn't mind seeing his style against GGG. Offense versus Defense.
Distilled to its essence though, what @Ron Swanson is also saying is at some point (and he was so confident in GGG's ability that for him it was sometime in 2013) it becomes less-and-less exciting to see GGG beat up good, but-not-great opponents. I don't disagree. It's now reached that point for me. The problem is I don't see an easy solution.
I also agree with @Ron Swanson that the middleweight division isn't great right now. It's not as bad as he makes it out to be, but it's clearly not the featherweight or the flyweight divisions.
So, who does GGG face? Let's assume Ward is out due to contractual disputes with his promoter. Same with Junior. It looks like Froch won't face GGG. Mayweather won't face him. Cotto won't face him. Canelo won't face him until 2016 is what I'm told.
Where does that leave him? To me, there are three satisfying doable fights available to GGG around 160-168 the he could take in the meantime while the Ward/Junior situations works itself out. Murray, Kessler, and Abraham. Do Murray in Monaco in February and Kessler in Denmark or Abraham in Germany later that year. Those aren't the only super middleweights I'd consider, but they have belts, and/or relatively big names.
With the exception of Murray, who is a big middleweight and the only available middleweight I'd want to see GGG in against, the thought process is that if he's going to take on good, but not great fighters, do it in the division above.