Thanks to 56Coop for pointing out this article.
As Packergeeks wrote in an earlier post (citing an anonymous source inside the Vike’s organization), Favre has already signed with the Vikes and now it’s just a matter of Favre/the team announcing it. Read here from NBCsports.com, quoting profootballtalk.com. They too indicate the deal has already been completed but that they just want to wait for the right moment to announce it.
If you have any doubts about the veracity of these claims, read Brad Childress’ comments in this article.