Creative Assembly are planning, as per usual, to continue adding to their next game - Total War: Warhammer - via extensive post-launch support following its planned release on PC on May 24.
As you might expect, the studio is planning on adding plenty of paid-for content, although today it was revealed that there will also be several free DLC drops that will include "additional new units, Heroes, Legendary Lords and even an entire new playable Race."
Obviously the new playable race is the most significant free addition planned, and according to a blogpost it'll be landing around the end of the year. The image below (which is, naturally, subject to change) offers a rough idea as to how the upcoming free content will roll out.

The studio also outlined its plans regarding paid-for DLC. Here's what it had to say about the content we're likely to see in the months after launch:
Lord Packs - Themed on a specific rivalry or conflict from the Warhammer Lore, Lord Packs contain brand new Legendary Lords and supporting units and characters for existing playable races. They typically include:
• 2 new playable Legendary Lords with their own narrative quest chains, campaign bonuses and quest items.
• 2 new Lords to serve as generals.
• A new unique Unit.
• New elite Units of Renown*.
'Units of Renown' are elite versions of otherwise already existing units. They might have upgraded stats, different arms or armour, or an unusual ability or two. Typically they'll reflect the theme of the Pack, probably having been instrumental in the conflict. Given their power and rarity, you might only be able to field one unit of them at a time, or they may be subject to other restrictions.
Race Packs
Race Packs introduce a new playable Race to the game, either as a first appearance, or adding a full Unit roster, Heroes, Lords and playable Legendary Lords to non-playable existing races in the core game. They might typically include:
• A new playable Race added to the Grand Campaign and Multiplayer game.
• New Legendary Lords with their own narrative quest chains, campaign bonuses and quest items.
• New Lords to serve as generals.
• New Race-specific Heroes (where applicable).
• New magic items and mounts.
• Race-specific unique Units.
• Race-specific building, technology and skill trees.
Campaign Packs - A supercharged version of a Race Pack, Campaign Packs not only contain a brand new Race for use in the Grand Campaign and Multiplayer, but also add a new Challenge Campaign to the game. Themed on an epic event from the Warhammer Lore, these self-contained Campaigns will present a distinct and challenging scenario. Contents might typically include:
• A new Challenge Campaign featuring the Pack's new Race; a self-contained mini-campaign, with a set of escalating victory conditions to suit both new and very experienced veteran players alike.
• Adds a new playable Race to the Grand Campaign and Multiplayer game.
• New Legendary Lords with their own narrative quest chains, campaign bonuses and quest items.
• New Race-specific Heroes.
• New Lords to serve as generals.
• New magic items and mounts.
• New Race-specific, unique Units.
• New Race-specific building, technology and skill trees.