I see them together. More than LeeSaku, I presume. Sakura can changed, but still like( WHO CAN BLAME HER?!) nice looking men, what exlude Lee. And she - Sasuke... Itjust CAN'T happend. Maybe he is somewhat "good" again, but never seems romanticly involved with her( if he not thinking about Itachi, than about Uzumaki - not to mention his style - it all just screaming GAY... Also he is something alike to what you can name samurai what just make me remember about Edo and what was one of the MOST significant trait - homosexuality. But it wouldn't make girl to stop be head over heels for him ).
Back to business - SaiSaku would make sens. Also Sakura love to talk other human beeing what to do - Sai's social retardation will make him be very grateful of that. Another plus. ^.^