In a way, I hope Harry doesn't become a prefect...Harry's got to get used to not having everything simply because he's Harry (what someone mentioned about bending the rules)...I don't want him to turn into a Draco, and I don't think he (Harry) does either!
What if Harry replaced Ron as prefect? What message does that send? That Ron was just a substitute for Harry as Dumbledore thought Harry had too much to handle? I feel bad for Ron because that's essentially what happened...Ron wasn't Dumbledore's first choice...once again, Harry eclipsed Ron. Only Ron (to my knowledge) doesn't know that...yet. I sort of hope he'll never know...why not let Ron have something that Harry doesn't have? Don't get me wrong, I love Harry, and I think he's a great kid, but I think there are other ways for Harry to shine (being Quidditch captain eventually, for instance, or letting him continue with the D.A., as someone mentioned). Just my opinions, of course, and nothing against Harry, it would just be a shame for Ron to feel second best yet again...
Then again, on the other hand, if Harry truly is worthy of being a prefect over Ron, then I suppose Harry shouldn't be cheated either. Considering Harry breaks more school rules than Ron does, I'm surprised Harry would be a prefect, but then, Harry's really excelled (in his service to the school with all his showdowns with Voldemort), so perhaps he is deserving. I'm rather confused now!
ARRRRRGGGGGGGGGGH!
~ Lizzy