Somewhere in the Patsfans.com archives is a thread I started asking the question, "is the S becoming more important than CB to defenses. It was a couple of years ago and in response to how offenses were routinely cutting up defenses in the middle of the field.
This was a very good article. But I think its less about labeling positions in the defensive backfield, and more about the fact that all members of the defensive backfield need coverage like ball skills. All the things you look for in a CB today, like length, hip turning, the ability to play press man, etc; are things you are now looking for in your safeties.
Also no longer can you differentiate safeties into FS/SS skill sets. Your "other safety" needs to do more than just play in the box in run support and cover the plodding TE's that used to be the norm in the NFL.
I think as time goes on, secondaries are going to be filled with just generic DB's who will be used to play in more amorphous-like defenses, that don't rely on set positions. Also there was a time when teams might have as few as 8 DB's on the roster. Recently that number was raised to 10 on most rosters. In the near future I can see it rise to as many as 12. Defenses will break down into 2 kinds of skills, pass rushers and pass coverage.
Run stuffing DLmen and LB's will become merely situational players and their value decreased. This is why Spikes isn't here anymore, one of the reasons why Vince got his pay cut, and the reason why I don't want Louis Nix at 29.
If you look back on it, this article confirms why BB placed such a high value on a CB/S guy like Tavon Wilson. The fact that it didn't work out (at least to this point), doesn't negate that BB was once again ahead of the curve in looking for exactly the player Pompei is describing. Don't forget that in just 2 years of rather limited snaps on the regular D, Wilson has accumulated 5 picks.
Once again it looks like BB is loading up on DB's who can play multiple positions in the secondary. This becomes even more valuable when you add a true shut down CB in Revis. Now the Pats secondary can be even more creative, and a bigger mystery to opposing OC's
BTW- just a interesting note to ponder. Did you know that despite losing BOTH starting DT's early in the season, the Pats managed to get 14.5 sacks out of their DT's last season. That is a much bigger number IIRC than previous years. I think it shows a couple of things. First the Pats made it a bigger priority to create inside pressure and create more opportunities for the DT's to rush. Second guys like Chris Jones, and Siliga (who accounted for 9 of those sacks, are a lot better than you'd think. Finally our DE's did a great job of forcing QB's up into the pocket.