Hello Tenno
Tenno con is on August 1st and Warframe has already teased the upcoming expansion. Its call The Heart of Demos, and all I know is that its related to the infested faction. Also for tenno who tune into their stream for 30 minutes on August 1st with their twitch accounts linked to Warframe will get a free Hydroid Prime. they have other giveaways but I'm not sure at this time how to get them.
Here is the link to where I got my information for those who want to read about it there.