This is pretty much the biggest trade I can imagine. In some ways, it's bigger than the KG trade. It's a complete reset of the whole roster (or it will be, if they can find another NL team to give Lackey away to).
What I worry about is whether the team is going to waste that flexibility this winter. I'd almost rather them take a break; Red Sox nation can accept (I believe) a year of rebuilding/development. Let's see the young guys, let's give them a chance to develop. Re-focus on the things that made Boston successful at the beginning of Theo's tenure, player development and smart, low-risk signings rather than trying to match the Yankee model.
But really, if they can get rid of Lackey... Dice-K's going to be gone next year, too. Thank freakin' god!