Not offering up anything that hasn't already been covered, but just going off the top of my head and glancing at the standings...
Positive surprises...
Washington - Not sure why they are so good.
Winnipeg - Although I guess they are a team that will have to do something come playoff time for their season to be viewed in a positive light.
Wild - Cooled off as of late, but didn't think they would be a head of Dallas, Colorado (until recently was probably a negative) and Nashville (see below) in the Central.
Negative surprises...
NY Rangers - Made the ECF last season, really good start this season, and then the wheels just came off.
Nashville - Really didn't know what to expect after going all in on FA, but surprised they just straight up suck.
Detroit - I dunno, I guess I shouldn't be surprised. They have become one of the league's preeminent wheel spinning franchises.
Also...
Out of the two perennial Atlantic doormats, for some reason I thought Buffalo was more likely to be flirting with the playoffs. So Buffalo negative, Ottawa positive.