I agree with Devildad about Timby, but based on their playoff run last year - it's not a complete surprise... Quite a few underclassman last year on that team... Salem's up'n'down though - they've beat the teams they're supposed to recently, but lost to better teams (Timby, Merry, & Memorial).
Merrimack on the other hand has gone 40 innings without giving up a run (see
http://www.nh-highschoolsports...win-over-winnacunnet) - that's pretty impressive. Not sure if it includes the 4 innings of the 4-0 lead they have on Keene.
As for North - obviously the BG game for "local rivalry" could be tough and they do have South next Friday to conclude the season in another rivalry game. They are in the driver's seat to the #1 seed and a possible repeat of last year's run. The current standings have #1 North, #4 Timby, #5 Merri - that could be a tough path barring upsets.