A brief clip gives an idea of the gameplay ramifications of Madden NFL's new "swagger" stat. In short, it's not much, but at least it doesn't seem to be limited to scoring situations.
Bottom line, this is a set of animations attached to a branded stat. They do seem to be player-specific: Chad Ochocinco and Adrian Peterson behave consistently with their scoring poses (although, with Ochocinco, what really is consistent?) From a marketer's standpoint, it's a nice tie-in: They're assuming when you see the signature posturing, you'll think to yourself, I saw that because of the Old Spice Swagger stat. And because we're beating the drum about in-game advertising prior to release, I'd say that's a good assumption.
Silver lining? The only way the NFL's staid approval barons would consent to more lifelike showboating in the game is if they were getting paid, and as said before, Old Spice's "swagger" campaign pre-dates Madden, back to a marketing deal with the league in January.
Madden NFL 11's New Swagger Rating [Game Informer]