I don't think you will see a complete overhaul of the major league roster next season or anytime in the forseeable future -- unless the Sox were willing to dramatically reduce ticket prices. I've read on this board thousands of times that "Sox fans will not support mediocrity." I read it again today. Realistically, this year is proof that Sox fans may not even support a team that spent much of the summer in first place -- or at least will come up with dozens of reasons to not show up to the ballpark (and a few of those reasons are IMO legitimate).
The Cubs can go through a major ovehaul and still draw close to 3 million fans a year. If you blow up the Sox roster and offer the fan base absolutely no hope of contending, the Sox will draw less than 1,500,000 for the season -- unless the Sox were willing to slash ticket prices. I just don't see it happening.