Regardless of when it happens--whether it is this year or any other--I have a wish that I doubt will come true, and before anybody goes ballistic, this is simply my opinion....
I would prefer the show to end without *any* of the 6 being paired with each other.
The reason that I believe this would be the best ending? I really don't think that C&M bring out the best in each other now, nor did R&R bring out the best in each other when they were together.
I think that this is most apparent in C&M lately--she has morphed into a loud, screeching shrew while he is led around by his ear. He has lost his sense of humor (helped along by the writers) and seems to be little more than Monica's pet. These characters have clearly changed for the worst since they have been together.
I also think that Ross and Rachel expect different things out of life--I'm not sure if he has ever appreciated her career--I think he has always expected everyone to respect what he does at the musuem without giving her the same consideration--granted, she's no doctor of anything, but that's not for him to judge. More importantly, I think that his jealousy and insecurities will make it hard, if not impossible to be with a world-class flirt like her. (And that insecurity is clearly still there--witness the episodes with Elizabeth)
Ash