Microsoft are set to pass on this year's Tokyo Game Show, which is set to run between September 17-20. Microsoft Japan's Masayuki Inoue confirmed as much to Famitsu (which then came to us via Gematsu) when saying:
"This year, Microsoft will not exhibit the Tokyo Game Show, but we're making various preparations to deliver the latest Xbox news to fans and media. We will provide an update as soon as we can."
Either the platform holder is planning on hosting their own show in Japan, or they've designs on doing something akin to Nintendo's strategy during E3, and will reveal their news via an online broadcast of some description. We'll update you with more details as and when we have them.