Most significant signing: The Vikings filled two major holes on defense last week, adding former New York Giants defensive tackle Linval Joseph and former Carolina Panthers cornerback Captain Munnerlyn. As important as both will be to the roster, Munnerlyn should help solve one of the Vikings' biggest problems from last season. He can line up at slot cornerback on third downs, where teams routinely targeted Josh Robinson last season. Munnerlyn also gives the Vikings the kind of scrappy tackler against the run they had for years in Antoine Winfield.
Most significant loss: Jared Allen will be the Vikings' most high-profile departure, but it's difficult to tell yet how much that will affect the team. New coach Mike Zimmer's system wouldn't have featured Allen the way he'd been used over the past six years in Minnesota, and the Vikings should have their starting defensive line in place with Everson Griffen, Sharrif Floyd, Joseph and Brian Robison. Still, it will be strange not to see Allen lining up at right end in a Vikings uniform this fall.
Biggest surprise: It's been clear for some time that the Vikings wanted to re-sign Griffen, but the value of his contract -- which puts him among the highest-paid pass-rushers in the league -- was something of an eye-opener. Griffen will get $20 million guaranteed as part of his deal, though the Vikings put all that guaranteed money in the first two years of the deal. Griffen's best year in the NFL came in 2012, when he posted eight sacks in a part-time role, and he's yet to become the kind of dominant force the Vikings are paying him to be. The contract is a gamble on potential, but the Vikings are obviously confident in Griffen's ability to fulfill it.
What's next: The Vikings still need help at linebacker, though general manager Rick Spielman sounded confident in his young linebackers last week. They remain in contact with former Bears defensive tackle Henry Melton after hosting him on a visit last week, and they will bring in Jets offensive lineman Vlad Ducasse for a visit this week. It's also possible the Vikings look at a corner, and they'll still be in the hunt for a young quarterback come draft time.