While Supergirl moved networks from CBS to CW in a recent announcement, there are already big plans for the second season. Supergirl will be visited by her cousin, Superman, in the first two episodes of the new season.
Andrew Kreisberg revealed the news this morning, via Nerdist, that Kara will be joined by her cousin, Kal-El: "Greg [Berlanti], Ali [Adler] and I are beyond thrilled to welcome Clark Kent and his slightly-more-famous alter ego to the world of Supergirl. Superman will be appearing in the first two episodes of the new season and we cannot wait to see who next dons the red cape."
There's no news yet as to who will play the Man of Steel in these opening episodes. The chances of Batman v Superman star Henry Cavill reprising his role are slim to none, considering the huge differences in tone between the films and television series, among other things.
Superman did appear, in silhouette, in the first season of Supergirl, when it was on CBS. The character is mentioned numerous times during the season, so his inclusion makes sense. Now that the show is on The CW, the network has expanded their DC television universe immensely. Supergirl is now part of a longer list of DC shows including Arrow, The Flash, and DC's Legends of Tomorrow.
More than likely, there will be a casting announcement within the upcoming weeks. Supergirl returns to television this fall.