Okay, lets start this.
I am a Redskins and a Bills fan (70-30 Redskins) so this doesn't concern me at least until the Redskins and the Vikings go to the playoffs.
Brett Favre has been in the NFL for the past 19 seasons (1991-present), earning 2 Super Bowl appearances (XXXI, XXXII) , one Super Bowl victory (XXXI), 3 AP NFL MVP (1995-97), many Pro Bowl appearances and many NFL records (TDs, QB starts, yards thrown, interceptions). Although it is now a summer drama seeing Brett Favre retire, unretire and reretire in January, he just wants to play the game and sometimes his 39 year body affects that decision. The main reason that Minnesota took this initiative is because with a sufficient run and pass defense, decent receivers, and probably the best RB in the league (Adrian Peterson), the QB position is the only position that the Vikings needed to meet to become contenders in January. The Vikings won the NFC North due to the play of veteran backup QB Gus Frerotte and Adrian Peterson. Now that Frerotte is a free agent and QB Tarvaris Jackson and Sage Rosenfels (who was a good backup when playing with Houston) can't prove themselves as sufficient regular season starters, Favre was the needed piece to the crazy puzzle in the Minnesota Vikings. With Jay Cutler, Aaron Rodgers and 1st overall pick Matthew Stafford in the same division, Favre can show that competition. And if Favre reretires for the third time at the end of the season, Minnesota can always draft a QB since Colt McCoy and Tim Tebow could declare for the NFL Draft after completing their senior years.