WHO GOES FIRST?
From Wizkidsgames.com: "Now, the person who wins the roll chooses – do they want to pick the map and go first or would they prefer to let their opponent be the one who picks the map and goes first. And the player of a themed team will have a better chance at making this important decision."

THEME TEAMS (BUILDING)
Keyword-Themed-Teams are based on 300-point team builds. From Wizkidsgames.com: "If you are using a generic keyword, then you’ll need 3 characters on your team. If you are using a named keyword, then you’ll only need 2. (Wait a sec – what’s a named keyword? It’s a keyword that is not a generic keyword!). For build totals of 400 through 600, that number doubles (6 characters for a generic themed team, 4 characters for a named themed team). And so on."

All of the "Theme Team Bonuses" still apply, but with a major change to the Probability Control Bonus (see below).

THEME  TEAMS (PROBABILITY CONTROL)
Best to just quote Wizkidsgames.com on this one:

Like the rules for building a force, the number of uses of Probability Control a themed team gets depends on the build total. Build totals of 300 points or less grant generic themed teams 1 use of Probability Control and named themed teams 2 uses. Again, like the build requirements, this would double for build totals 400 through 600, triple for 700 through 900, and so on.

How Probability Control can be used through this mechanic has a number of changes.

1) The character using Themed Team Probability Control (TTPC) must possess the keyword that makes up the team. So Bystander Tokens will not be able to use it, as they don’t have keywords. Also, if your force was built to a keyword (say, Doom Patrol) and a character changes so that they no longer have the keyword (say, Beast Boy changes to his non-human form), while the team is still a themed team and can use TTPC, Beast Boy in his animal form would not be able to help out with TTPC.

2) The character using TTPC cannot have been given a non-free action (free actions will no longer prevent the use of TTPC). This makes the use of the TTPC a bit more flexible than it used to be. It will still prevent a character given a non-free action with, say, an attack roll from using it, but if a character is being given a free action (like Leadership) they would be able to use TTPC on their own roll. New players especially had a lot of trouble distinguishing between using Outwit and a Close Combat Action as both being “actions”, so we’ve decided to “go with it” for simplicity. If you’ve been given a tokenable action, you can’t use TTPC. If you’ve done free actions, you’re still ok.

3) A character that can use Probability Control already cannot use TTPC. The idea of a single character having access to multiple uses of Probability Control each turn was never the intended purposes for Themed Teams. The occasional reroll? Sure. But some teams were able to set themselves up for 5 rerolls for one attack roll (or more). If you want that much PC, by all means, put the appropriate characters with that power onto your force. But keywords alone are not going to get you there. As a corollary to this rule, there’s also a rule stating that a character that has already used Probability Control this turn can’t use TTPC. This covers some additional corner cases involving Edward Nigma/Warbound, damage from Krakoa, and prevents the same character from using TTPC twice in one turn. To be clear on this, a force is allowed to use TTPC more than once for a given attack, but you are going to have to use different characters and none of them can be ones that can use PC on their own.