Harvin wanted out of Minnesota, and the Vikings got a very nice haul in exchange. (A 2013 first-round pick, in addition to a '13 seventh-rounder and a mid-round pick in 2014.) That was the easy part.
Big spenders at wide receiver
Harvin was the second-best player on the Vikings when healthy last season. The team had the worst passing game in the NFL with Harvin, and their wide receiver position is barren now that he's gone. Luckily, it's only March.
General manager Rick Spielman would only make this move if he was confident the Vikings could re-stock the shelves right away. They are expected to make a run at Mike Wallace, although the Miami Dolphins probably are the favorites. If Wallace falls through, it wouldn't be surprising to see the Vikings (over)pay Greg Jenningsand use one of their first-round draft picks at wide receiver.
Wallace has a similar skill set to second-year pro Jarius Wright, who showed potential last season. Other than that, their cupboard practically is empty at the position. The team cut Michael Jenkins. Jerome Simpson is a free agent. The Vikings don't need a receiver; they need three of them. Teams make mistakes when they draft or sign out of need.
But the Vikings have no choice. They have to put significant resources into adding wide receivers. That was true even before losing Harvin.
More pressure on Christian Ponder
The Vikings have tried to spin Ponder's struggles, but his lack of development last season should be the organization's biggest concern. Perhaps the team believes that Harvin was going to be a distraction, but removing Harvin only makes Ponder's life tougher. There is a solid offensive line in place, not to mention MVP Adrian Peterson. Kyle Rudolph is a great long-term answer at tight end. But Ponder is going to have to win with new weapons out wide. That's not easy.
While the team publicly has stayed committed to Ponder, don't be surprised if they bring in a strong backup quarterback like Matt Cassel in case Ponder struggles again this season. Trading Harvin certainly won't make Ponder's job easier.