Final Fantasy XV for PC comes out on March 6th (updated)

FINAL FANTASY XV WINDOWS EDITION will come out on March 6th on Steam (store page), Windows Store (store page) and Origin (store page) for $49.99 (source) and will include every update and additional content released for the game so far.

The official trailer is available HERE
The official minisite is HERE

The official system requirements are:

Nvidia posted a detailed article with a description of every Nvidia-exclusive feature this title will use.

There's a benchmarking tool available to check performance:

"With this benchmark tool, you will receive a score which will indicate the performance index for operating FINAL FANTASY XV WINDOWS EDITION on your PC."

The preorder will go up on February 1st as well, and that will include store-specific bonuses. It is unclear if they will also be available as paid DLC.

• Windows Store – By pre-ordering through the Windows Store, fans will receive the bonus “Final Fantasy XV Powerup Pack.” This pack contains items designed to power up the player’s performance in combat.
• Steam – By pre-ordering through Steam, fans will receive the bonus “Final Fantasy XV Fashion Collection.” This pack contains a selection of outfits for the prince and his pals.
• Origin – Those who pre-order on Origin will receive the bonus “Final Fantasy XV Decal Selection.” This pack contains an array of cool and colorful decals for the Regalia. More details on the early purchase bonuses will be available at a later time.
• The physical version, which comes with a Steam key, does not include preorder bonuses.

EDIT: It looks like the items for the Steam version will actually take advantage of Steam's inventory system, as there are some test items displayed on the game's steamdb page
EDIT2: The game will have official mod support as confirmed here
EDIT3: Added link to the benchmarking tool