First and foremost, It means that the Cardinals' front office and head coach Bruce Arians think that they are closer to winning than most of the fan base or media does.
Palmer allows Arizona to make use of a very good wide receiver group lead by Larry Fitzgerald, Michael Floyd and Andre Roberts. The Cards also have a good catch-first tight end in Rob Housler. Getting the ball to Fitzgerald can't be overlooked. Last season, Fitz had only 71 catches and four touchdowns, hardly the numbers that you would expect from an elite receiver.
Acquiring Palmer allows the Cardinals to invest all of this year's draft picks into this team without reaching for a QB in the NFL draft. Arians made it very clear that Palmer is the starter putting any QB competition to bed immediately.
Palmer was simply the best of all of the options available to the team for next season at the smallest cost. Now that may not seem like it is saying much, but the Cardinals have made the determination that Palmer gives the 2013 Cards the best chance of winning. It is hard to disagree with that assessment.
The immediate impact is that the Cards aren't afraid to gamble and Arians' quotes concerning this draft, where none of the quarterbacks in the draft made the Cardinals' coach go "wow", seem to be legitimate.
If the Cards felt that there was a QB that they could pick and develop in this coming draft, they would have probably passed on having Palmer, Drew Stanton, and Brian Hoyer all under contract with Ryan Lindley in limbo.
Stanton seemed to be Arians' pick to be the quarterback a couple of weeks ago, making it clear that he felt that Stanton could be the starter. Now the Cardinals have simply avoided putting all their chips on one QB. Palmer is the starter, Stanton is the backup and Hoyer might be dealt if the team feels that they can afford to do that.
The fact that the Cards want to get a closer look at USC QB Matt Barkley in a private workout is curios in light of the Palmer trade, but maybe the Cards are covering their bases or this was part of the plan all along. I can't see Arizona using their first-round pick on Barkley, but maybe they feel like he will be there at the 38th pick.