Chelsea being on the 3rd, Arsenal being on the 4th and Nottingham Forest being on the 5th is probably the biggest surprise of this season so far. Let's see how it shapes going forward. I really want to see Nottingham Forest be one of the top four teams. Chelsea and Arsenal both are not playing very well, they have only one win each in the last 5 matches. So I think they do have a chance 
The most suprise for me there is Chelsea as they didn't look like a team that could be in the top 4 position this season although they shouldn't celebrate yet as they're on th same points with others below them and one game lost alway from falling off the top 10 position as other teams are just one point below while others are two and three. The table position is going to be different after the international break as players will return back having injuries or feeling tired and they can't perform as they use to do. making other teams to have the opportunity to go up the table.
Chelsea getting to top 4 right now is also a surprise for me because before the beginning of the league the team was not looking like they will have a good season but having seen the turnaround that the team has experience so far and the form of the team you don't expect nothing but good results from them.
The point difference between the teams is no different but coming back from the international break there will be a lot of injuries which may affect the results of some teams but then a team that has good 1st and second 11 players shouldn't be affected and I think the Chelsea team is filled with players even though some of the players are not known.