As the images from the newly released Coro Coro are on the run, more important information on Pokémon BW2 has been released!
First, on the early events - it appears as if Alder appears early in-game and asks the player to follow. The old side-protagonists Cheren and Bianca are expected to make an appearance!
Bianca will be the one to deliver unto the main protagonist their starter Pokémon while Cheren is making a reappearance as a Gym Leader, of what appears to be the Normal-type. As you can see, some aesthetic differences have been made, such as Bianca's new glasses, and Cheren's lack of them.
Team Plasma is also confirmed a reappearance; N, however, according to what appears to be one of the Seven Sages, is still nowhere to be found. Whether he will reappear in game is still questionable.
The "Genie Trio" has been given new forms as well. The original forms are now called the "Incarnation Forme" while the new, winged forms are the "Sacred Beast Forme". They will appear in the new Unova Pokédex, in positions 198, 199, and 200. According to the page, the new forms have boosted defenses and speed in comparison to their Incarnation counterparts.
Next up, there's PokéWood, which is the replacement for the Musicals in BW. Basically, it appears as if you have to face a giant Mecha-Tyranitar. Brycen (Icirrus City's Gym Leader) and Homika's father (father of the new Poison-type Gym Leader) appear at this event. Basically, in PokéWood, you record your Pokémon battling the Mecha-Tyranitar and turn it into a movie.
Finally, some old Champions and Gym Leaders are expected to make an appearance, though all the details are unknown as of yet. There is supposedly a facility at which one can face the Champions of Kanto, Johto, Hoenn, and Sinnoh, along with some memorable Gym Leaders, as shown here, Giovanni, Volkner, Brock, and Misty.