Hmm I think RSyaoran and CSyaoran maybe will merge into one so they can both be happy!
I'm not for the merging theory - I think that the two Syaorans are two separate individuals (seeing as how raising does affect one's personality, and Our Syaoran and Real Syaoran sure had different childhoods), that is, if Our Syaoran ever comes back. His clone side, albeit being his true self, I don't count as being a real person since it's hardly more than a machine, a copy that could be destroyed with no loss of the original whatsoever, thus making a merging pointless since a machine would add nothing to Syaoran's personality. Then, if Our Syaoran does come back somehow, the merge could be a possibility.
As for which one I want Sakura to end up with, I'm terribly, terribly torn. Yes, I support the fluff. Yes, Our Syaoran is the one who has loved Sakura all this time, and is the one she loved and has come to love again, however, I wouldn't say no to a bittersweet ending such as Sakura always having to live with the knowledge that her beloved isn't the 'real thing' to her. I can't make up my mind, although I'm kind of swinging towards the fluff...