I still have 3 weeks until I graduate, and then I have to go back for summer school.
Anyway, high school isn't as bad as 8th grade teachers make it out to be. The material may be a little harder, but you basically have about the same amount of work. I actually found 10th grade to be easier than 8th grade, honest.
High school is a completely different atmosphere in most cases. Middle school is all about cliques and popularity, while in high school those 2 things are less important. Although there are still cliques and popularity issues in high school, many people mature enough to ignore a lot of it.