No offense longtimefan but IMO your summary missed the most important changes and mischaracterized a couple of others:
The link mentioned that Wilson was inactive because of a groin injury not because he got demoted. Of course I’m rooting for Worthy but I would caution about evaluating his play vs. the Bears’ OL vs. evaluating Wilson’s against a much, much better OL, the 49ers. I’m not sure the staff agrees that Wilson is “out”.
Nick Perry got reduced snaps because of Walden’s return but also because he injured his wrist against the 9ers and was wearing a protector. Obviously his hands and wrists are extremely important to his game, particularly because strength is his the best part of his game (as opposed to coverage or finesse rush). Don’t get me wrong, Walden is the better pass rusher but IMO it’s incorrect to characterize Walden and Moses “in” and Perry “out”.
IMO the three most important changes were:
Shield’s play against the 49ers did indeed earn him the starting job as some of us posted (or hoped) after that game. While Williams and Burnett handled Marshall, Shields was mostly left one-on-one against Alshon Jeffery, the rookie WR the Bears are so excited about. Jeffery had one catch for 7 yards. Shield’s ascension is huge – his poor play in 2011 was due to his unwillingness to tackle and apparently his unfamiliarity with anything other than coverage (eg base defense). IOW he was a fantastic sub in ’10 because all he had to worry about was covering receivers. It took him a while but his off season talk about improving his tackling and willingness to do so has been turned into action. If he keeps this up this is fantastic news – along with Williams return to health they’ve significantly upgraded their starting CBs without making a personnel move. Their improved coverage will "improve" the rush of the DL and LBs.
The one of the four changes mentioned in the link you didn’t list was second most important IMO: McMillian taking over for MD Jennings is another significant upgrade. Unlike Worthy vs. Wilson, we saw McMillian outplay Jennings vs. the 49ers. McMillian brings a physical presence and displayed a nose for the ball. Again, we shouldn’t get too excited because it was the Bears’ offense but the experience McMillian is gaining should continue to pay dividends throughout the season.
The next most important change is also significant IMO. Casey Hayward took over for Bush as the sixth DB in sub packages. On many teams that wouldn’t be as big a deal but because the Packers will play nickel and dime a lot this season it is for the Packers. Beyond that, the more experience Hayward gets, the better. Bush is a great STs player – lets hope his playing time is restricted to STs going forward.
I’m concerned about how House’s shoulder brace will affect his play but at some point his shoulder will heal and when it does he’ll push for playing time. With Shields’ improved play, House’s return at some point, and Hayward getting experience, the young CBs look very promising for the future. And Tramon is only 29 years old.