Personally I'd have to say the change was a good one, if only that it may shake the team up and get them out of this slump. Jimy was a good manager, and will certainly be employed again in the near future if he chooses to get back in the game, but he was not a good fit in Boston. In a town that is baseball mad, explaining every oddball move - good or bad - with the ubiquitous phrase "manager's decision" just didn't fly. Kerrigen is stepping into an unenviable post - and Duquette is taking a huge risk - if the Sox don't make the playoffs they both could be gone. I admire the Duke for that - he could have waited until the end of the year, missed the playoffs, and had Jimy take the fall. Sox fans say what you will about him, but the Duke has proven time and again he wants to win, and win now.
I've always felt managers have a limited impact on the game (or should anyways) - the players are the ones out there. Boston was ready to lynch Jimy after Lowe blew that game against Seattle this week - but had Lowe held on he would have been a saint and Jimy most likely still had his job. How many great managers are out there coaching bad teams? How many bad managers get lucky and are given talent? It's the players who will ultimately decide the Sox fate this season, so maybe this move will light a fire under them... too bad they're down 3-0 to the O's right now.