The leaked photos confirms that 19 teams will be included in the box, which means all but one of the 20 existing teams in Blood Bowl will have rules in this edition. It appears that the individual player cards have been replaced with team cards which will have all the stats for every player on the team.
In addition to some stat tweaks to a few positions on the Human team (the Blitzer is now Move 7, and the Catchers is Move 8), the inclusion of a brand new stat for every team is getting much attention - what appears to be a block stat (of 1) in shown for both the Humans and Skaven. This would allow certain players to roll a certain amount of block dice without the need of special text (see for example, the Black Orc). This also opens up possibilities for even stronger positions or players, such as Ogres. The fact that now three block dice (of a single color) are included in the game (instead of two block dice for each of the two teams) further supports the expectation that blocking rules have changed.
Further leaked images show a new "Rookies To Watch" card (which will help out inexperienced players) and the two pitches included in this edition.
If past timing is any indication, Blitz Bowl Ultimate Edition will release this fall. The original Blitz Bowl was first available for purchase at Gen Con 2018 (in August) and was later was available for purchase in early September 2018. Blitz Bowl Season 2 had an official release date of Monday, September 21, 2020.