Another thought is that Kakashi could be seriously injured....so much so that he cannot continue being a Ninja or at least not for some time. This would serve to make Naruto and Sakura grow up as well as he would be removed on a more permanent basis from any field ops thereby taking away his leadership in the field. I for one did not forsee Jiriya getting killed. I think it would be another huge shocker if Kakashi got killed and agree with Abdula's rationale as to why such event might actually take place. I could also see Tsunade going into the field to revenge Jiriya's death and perhaps getting killed. She is hot tempered (though less so since becoming Hokage) and I think that she really loved Jiriya both as a friend and perhaps on deeper levels than even she may have been aware. Tsunade is ultra strong but we have not seen how well she handles Genjitsu.

As far as Sakura is concerned. I think both she and Naruto may have to accept that Sasuke is no longer the person that they both once loved. This and the potential of losing Kakashi seems like the two events that would force the two of them to grow up.