Read on for the metric ton of info that was revealed, and teased, by the developers, including diagonal movement and multiple rivals.
http://www.nintendoworldreport.com/news/34585
A lot of specifics were rooted out in the Q&A session of Nintendo's Tuesday evening Pokémon Roundtable.
For example, Pokémon X and Y will use your pre-existing 3DS friendcodes automatically, so players can start building their connections even now before the game comes out.
In response to additional questions from the audience, the panelists revealed that Pokémon X and Pokémon Y will only have a single save file. They also revelaed that they working on allowing players to import their pokémon from previous games in the serious, but didn't provide any further details. Likewise, while the developers are exploring DLC, they had nothing to announce at the time.
However, they did reiterate that the new Fairy type class of Pokémon was introduced to counterbalance the powerful Dragon type. They added the new type to avoid having to drastically reduce the abilities of existing Dragon type pokémon.
They declined to declare the new total number of pokémon the games would contain. However, they did talk about how there would be player avatar customizations that would be visible when playing online.
However, it appears that the terrain and layout in the upcoming games will be based on France, a region chosen for its beauty. As for getting around, players would be able to move diagonally, though the game would still be grid-based. However, when using roller skates to get around, the movement would be more fluid. If the opportunity presented itself, you could also swing on vines. Players would also be able to ride pokémon and use their special skills to open up new transportation possibilities, such as Rhyhorn breaking rocks and crossing rocky terrain.
Music in the game will have an improved and different feel too,. The developers no longer felt a clash when working on the games between the game music and their computer workstation's music. And when you go to battle online, you can select which song you'd like to hear.
The developers were asked about whether players might see Pokémon Red and Blue on Virtual console, but it didn't seem likely. They acknowledged that a rival character would exist, but hinted that they wouldn't limit themselves to one. There would be a antagonistic "Team ____" organization but they declined to give further details on what changes we might see in that dynamic.