We have a title and a cinematic trailer.
Looks like the rumours were accurate.
Edit: a screencap from the trailer appears to show a human female and krogan companion 
edit: little late on this one due to travelling to work, but a blog with details from Bioware 
Edit: Some screenshots from the trailer and concept art - most has been seen previously but we have confirmation now its for ME:A 
Edit: Looks like we will have to wait until towards the end of the year for further details. 
EDIT: I should point out that this is a leaked image, and not direct from Bioware, but based on how accurate the previous reddit leak appears to have been I am linking it here as a matter of interest. If accurate it tells us how Andromeda and the ARKCON fit into the established timeline: 
EDIT: Beautiful new trailer for N7 Day 
EDIT: a blog with more artwork and the link to sign up for more details. 
EDIT: As of 22nd Dec Development Director Chris Wynn, who also worked with Microsoft and Epic as a producer on the Gears of War franchise, has left Bioware for undisclosed reasons and returned to the United States. No successor has currently been announced.
EDIT: Cameron Lee tweeted after playing the first hour of the game. Details here 
EDIT: Lead writer Chris Schlerf left the game in February to join Bungie, after only being with Bioware for five months.  Also Senior editor Cameron Harris has left not only Bioware but the game industry as a whole as of March. She was editing Storyline and Dialogue for Andromeda before her departure.  Finally renders unearthed from a forum post have shown the N7 character from the trailer, originally stated not to be the new protagonist, however labelled in the release as the "Pathfinder". 
EDIT: ALLEGEDLY this is our first footage of Andromeda gameplay. 
- Was due to release Holiday 2016, but is now delayed to Q1 2017 
- Has been in development since before Citadel's release in 2013.
- New adventure, taking place far away from and long after the events of the Trilogy.
- You will play a human, male or female, though that’s actually not the character you saw in the trailer.
- Krogan characters are confirmed based on various promo art.
- Exploring an all-new galaxy, Andromeda, and piloting the new and improved Mako.
- A new team of adventurers to work with, learn from, fight alongside of, and fall in love with.
- Both Game and trailer use the Frostbite Engine as previously established, and trailer "represents our visual target for the final game".
- Apparently being developed simultaneously by teams in Montreal, Austin and Edmonton studios.
- The game will feature dynamic weather.
- The game's multiplayer mode will feature not only the ME3 style co-op, but also an endless horde mode.