It won't.
People who think it's going to change the balance are just wrong, there'll be a handful of players that can really demand some money for their likeness (Zion for example).
Essentially it'll give them the ability to sign stuff and make pocket change, and also do appearance etc.
Just think about it like this.
NFL - 32 teams (53 man rosters) ~ 1696 NFL players
NBA - 30 teams (17 man rosters) ~ 510 NBA players
That's your two biggest sports in the US right now, less than 2500 players between them. NCAA over-sees 1268 schools with nearly 500k student athletes.
In short, Nike/Gatorade/Under Armour etc. are more likely to pay a professional athlete already at the highest level in their sport money than they would a student athlete who may not have much national name recognition outside the fanbase for his school.
Cause not even every NFL/NBA athlete has big time sponsorship money coming in.