Before we get too depressed about every significant free agent defensive end signing elsewhere, let us calm down and look at the Viking roster. The Vikings have struggled to get a pass rush in the past few seasons, and they should try to upgrade pass rushers at defensive end; however, they do have some competent players that can actually play the position. The DEs currently on the roster are Ray Edwards, Otis Grigsby, Erasmus James, Jayme Mitchell, and Brian Robison (Kenechi Udeze is on the roster, but naturally we won't include him on the active roster; we hope for his recovery and good health for himself and his family above all).
If that is the group the Vikes go into 2008 with, then defensive end will certainly be a team weakness. But those are players that can fill the position and occasionally make plays.
Keep in mind the defensive tackles on the roster are Pat Williams, Kevin Williams, and Fred Evans; while the Vikings should definitely work to improve their pass rush, defensive line is not an area that should make us quake with fear in the long dark night. The starting linebackers (Ben Leber, E.J. Henderson, and Chad Greenway) are strong too, which can also help cover up some of the weaknesses at defensive end.
The Vikes will also likely look at defensive end in every round of the draft. They must hope to find some rookie defensive linemen that can contribute right away, whether they are first day or second day draft picks.
But the biggest need is now quarterback: the Vikings must sign a competent backup for Tarvaris Jackson, and/or a quarterback that can push him for the starting job.