why are we complaining about sai now? we all knew it was gonna happen. however the part about naruto reminding him of his brother was way too cliche.
i dont think sai will die. not yet at least. now that hes a good guy he has too much of a role to play. after this arc is done konoha has some cleaning up to do. i think that the point of this story arc, plot wise, is not to bring sasuke back to the leaf, but to spark a cilvil war. sai will play a pivotal role in that seeing as how hes the only good guy with information on how roots works.
i predict that oro sasuke and kabuto (and maybe a few usless sound nins) will assist root in this war, and naruto will have to stay in konoha to fight. meaning this would be the best opportunity for the akatsuki to track him down. and isnt there a chuunin exam coming up too? that may play a role.
of couse i could be wrong and kishi may just have sai killed off in this arc... but what are the chances of that?