According to Pro Football Talk, the Vikes have around $30 million in cap room (man, Brzezinski knows how to manipulate those numbers). While the Vikings should (and likely will) spend that money judiciously, there need be no financial limitations to pursuing the players they want. There's room to get whichever available WR the Vikes think is the best choice (and the Vikes probably need more than one WR). There's room to trade for David Carr. There's room to get a TE upgrade and a DE that might rush the passer.
The madness begins at midnight.
PFT also chimes in with misplaced commentary:
"Still, we'd prefer to see teams spread that surplus around to key contributors already under contract."
As a general statement, that's a good principle (as stated in the previous post); I just don't see how it applies to the Vikings. First of all, the Vikings have been giving raises and extensions to players already under contract all season (most notably Bryant McKinnie, E.J. Henderson, and Kevin Williams). The Vikes have shown a commitment to secure the services of their key contributors, so I don't really know what the PFT writer is driving at in relation to the Vikings. Furthermore, this was a 6-10 team; the Vikes need to do all they can to pursue player to help them improve. They'd be foolish not to use that surplus to try fill obvious holes and secure clear upgrades. Teams like the Colts should do all they can to keep their own players; 6-10 teams like the Vikings need to add talent.
Update: via The Daily Norseman, Kevin Seifert of the Strib has a bit more on the numbers. Just a bit, though.