Unfortunately there has been no Tenchu related announcement at the Tokyo Game Show this year.
FromSoftware has only shown a new Armored Core and Steel Battalion so far.
Acquire has 4 games at the show: Shinobido 2, Sumioni, Gladiator and Totomono (Classroom Heroes).
Shinobido 2 is confirmed for a worldwide release. The game will be out for the Playstation Vita later this year. The TGS trailer is embedded below. Can you spot the flying ninja?
Sumioni is another game for the Playstation Vita by Acquire. It has a quite interesting art style and seems to be controlled with touch input and analog sticks. Check out the movie for yourself! It starts off a little slow, but there is gameplay shown towards the end. The music is quite catchy.