The Online Etymology Dictionary gives a history of the word "mess:"
"c.1300, "food for one meal, pottage," from O.Fr. mes "portion of food, course at dinner," from L.L. missus "course at dinner," lit. "placing, putting (on a table, etc.)," from mittere "to put, place," from L. mittere "to send, let go" (see mission). Sense of "mixed food" led to contemptuous use for "jumble, mixed mass" (1828), and figurative sense of "state of confusion" (1834), as well as "condition of untidiness" (1851)."
And that's what the Patriots' secondary looks like, a total mess. Shawn Springs, Leigh Bodden, Terrence Wheatley, Jonathan Wilhite, and Darius Butler. There are no #1 CBs in this mix. No #2 either. Gone are the days of Ty Law and Tyrone Poole shutting down the Colts receivers in one-on-one coverage. Even Asante Samuel and Ellis Hobbs look like Hall of Famers compared to this bunch.
Wheatley showed some promise in '08 before getting hurt. But all of these guys have "shown some promise" at one time or another. That's not the problem. CONSISTENCY is the problem. A defensive back that only covers well 2/3 of the time is utterly useless.
Without a steady pass rush, and a well-performing offense that tallies points and hangs onto the ball, these CBs are fucked, plain and simple.
But the safeties aren't bad. That's the one bright spot. Brandon Meriweather is pretty solid as a tackler, even though he struggles a bit in coverage. He's like Rodney Harrison in that respect. He made 83 tackles, forced 2 fumbles, and led the team with 4 interceptions.
James Sanders is slightly better at coverage than Meriweather. He's not a Pro Bowler, but he's a solid safety to have. Sometimes both he and Meriweather look bad because the CBs in front of them screw up coverages. But the safeties are fine, and always improving. Look for Meriweather to be a dark horse to make the Pro Bowl.
Teams with bad secondaries can win Super Bowls (See: New York Giants, 2007). They can also be very easily beaten.