As of now, the biggest surprise for me in terms of league position has to be Brentford: currently in 11th place with a points tally of 15 (from 11 games) and a goal difference of -2. The received wisdom just a couple of months ago was that the division was theirs & theirs alone this season. Early days, but it hasn't really worked out that way so far.
As we know from bitter experience, it can be difficult to recover from a PO trauma....Brentford had the double whammy of the last minute penalty as well.