The creator didn't feel there were major changes to the rules.
There are only a couple minor changes to the rules, and I can easily sum them up here.
The producer’s budget is now calculated differently. You sum up the screen presence of all protagonists, double that number, and add three. In other words: 2x(screen presence)+3.
Instead of a 3/2 split for traits, protagonists now have a 2/1 split.
Conflicts are now resolved via cards. Instead of odds, count red cards, and use hearts as trump if you have a tie. If there’s still a tie, look for the highest heart.
Instead of high die narrating, it’s now high card. Red cards beat black cards, hearts beat diamonds and spades beat clubs.
-- http://www.dog-eared-designs.com/pta-changes.html via the Wayback Machine - second edition was in 2005 and the site has been relaunched since
Net effect is that screen presence (between 1 and 3) in an episode matters about as much as character relevance (between 0 and 3 relevant edges/connections, rather than between 0 and 5) to narrative control.
But, while having fewer traits decreases the pressure to jockey all five of your traits into a scene for maximum cards, it also means that characters have less to define themselves. This can also be a problem with creating "dual-role" series where you have e.g. an edge and a connection within the Wonderful 100 as Wonder Red, and others in your civilian life as humble grade-school teacher Will Wedgewood. (Or, you know, inside/outside the operating room or the police force or what have you.) In that case you can probably just go 3/2 since they'll never all line up together, and brother, if they ever do, that's your moment and you deserve all those cards.
More importantly, however, the trump is reversed... kind of. Rolling dice for "odds are successes, lows break ties, high die narrates" means that rolling failures also means you're rolling higher numbers, increasing the odds of what in later development you might call a "mixed success", where you get what you want but somebody else tells you how you get it. But red cards are successes and they also win ties for high card, and high red cards win ties on successes.
Now, this could be deliberate. Moving from d10s to the d52 that is a pack of cards also increases the spread of results, to the point that even if trump went SCDH high to low, actually needing to use that as tiebreaker wouldn't be all that common. Narration is random but slightly favors the winning side, as opposed to before, when it slightly more favored the losing side. I can understand how that might be psychologically unsettling, even if the overall effect might not be that much of a swing.
Third Edition (in case)
Now, first and second edition were a year apart and third edition was ten years later. It's possible that huge gap might have been mistaken for a gap between first and second edition, so just a quick summary:
- Producer wins ties for red cards, and suits are standard bridge trump, SHDC high to low, which means red cards aren't favored over black cards for who gets high card.
- High card no longer narrates, which means you can't write fanmail and win writer's pen on a scene you're not in, and also removes the potential ebb and flow of "chase scene play", where you deal out cards in three waves and high card for the wave narrates part of the scene. Narration is now collaborative.
- High card is still a consideration because everybody's issue gets to come out in a bad way; characters also have an impulse, a destructive way they express their issue, and it's possible to have more internally-focused scenes where you fight against your impulse as well as more externally focused scenes where Perducci's getting away with the serum, after him! Red cards win whatever the scene's focused on, plot or character, high card wins the backburner aspect.
So, bit of a mixed bag there too, depending on what you like about second ed. Narration's no longer a thing that's really up for bid, but there's now the major/minor split providing some more guidance for how a scene turns out. Control no longer gets tossed to some fan who pulled the king of hearts, but responsibility no longer gets tossed to someone outside the scene, either.