In this Blog, I will go over what DE's Devstream revealed to us in 58. Ranging from Skins, to Catbrows. Please note, I may not have remembered everything.
In the Devstream they revealed that they are planning on adding skins to Valkyr, Rhino, Sayrn, and Trinity. I only managed to get a shot of Pre-Corpus Valkyr, it appears they added a tail to her, removed her claws and gave her boots.
The Devs have shown a picture of a possible Brawler- Based frame who utilizes punches and melee. One of the devs also mentioned that he could throw rocks, which could mean he is Earth-themed, (or he could be compared to Tremor (http://mortalkombat.wikia.com/wiki/Tremor) from the Mortal Kombat franchise. (Amusingly, during the chat, everyone was calling him the Bacon frame)
The Devs have mentioned that the Typhus Frame (from a long surviving Fan Concept) may make it into the game at some point (Here is a link to Typhus's forum post:https://forums.warframe.com/index.php?/topic/176524-warframe-concept-typhus-the-parasite-warframe-update-10072015/)
During the Devstream, they also presented concept art of a ruined Moon, with Orokin Tech surrounding it, and scattered all over the surface.
The Devs also unveiled a .gif of the Warframe App in action. It appears that you'll be able to keep up your profile's Credits, Platinum, in-game Alerts, News, Invasions, The Codex, Foundary (to keep up with its status?) Play Mini-Games(?), check your Arsenal, and your Kubrows. The Devs also said it will be FREE.
The Devs also touched base on Catbrows. They said that Catbrows themself have a cloaking mechanism, and will only be visible by scanners (Codex Scanner, Synthesis Scanner, and possibly Helios.) and will become agroed when spotted. They also mentioned that feral Catbrows feed on Infested mass/meat (Wheither it be Bio-mass that covers ship, or infested units is unclear) and that the Grineer use genetically engineered catbrows to clear out ships of infestations.
One important note is that Grineer Catbrows can be summoned by a Catbrow variant of a Drahk Master, and in order to see the Catbrows, the Master uses equipment to see them, which means invisible abilities like Loki's Invisibility, Ash's Smoke Screen, Shade's Ghost and the Huras Kubrow's Stalk are ineffective.
In the beginning and end of the Devstream, the Devs mentioned making additions to the Liset, they mentioned that the orbiter compartment (Where your Arsenal, Foundary, Mods, and Kubrow are located) will be expanded upon, allowing for more room and areas of customization (This reminded me of the TARDIS from Doctor Who, with a small ship on the outside that's bigger on the inside.)
Lastly, at the end of the stream, they displayed concept art for two new Liset designs, and theorized the possibility of called a Liset for support, such as air strikes and supply drops.