There are big plans for Killer Instinct this month as Fulgore, Story Mode, possibly a single player arcade mode and new costumes for Thunder and Sadira are planned to be released. No word yet on when all the new content drops but Adam Isgreen on his Twitter gave the fans a sneak peak at Sadira's new costume to hold us over until the official announcement.
My guess is that it looks like she may get some kind of Gothic Lolita costume. No word yet on what her accessories will be like or when the new costumes will be available. If the release is like the Spinal update, it probably won't come until the very end of the month.
Sadira is my main fighter in the new Killer Instinct so I am very anxious and excited to see the full costume and all the accessories that I can give her.