Manchester City, Chelsea, Manchester United, abd Arsenal are also going to buy some players I think. City had already bough three players I think while Chelsea and Arsenal are also making effort to sign more players. If all of them succeed with the players they are willing to sign, then next season will be an interesting season to watch because the competition will be tough.
I expect there will be a huge boost to the City and Chelsea performance next season. They bought so many players and tried to solve their last season problem.
About MU, not really sure on what they're building, but i believe they much more focus onto solve their attacking problem.
As for Arsenal, they look very passive. I expect nothing from them next season. Almost the same squad, and maybe the same result.