Blood Bowl 2 is an adaptation of the classic Games Workshop boardgame that mashes up the world of Warhammer with American football in to an orgy of violence and humor. There is also something related to a sport in there somewhere.
While the two previous added races were released as paid DLC the four upcoming new ones will be completely free for anyone that owns the game during their release. A pretty good deal if you're already a fan of Blood Bowl 2.
The four new races, most likely released in order, are: Norse, Undead, Nurgle and Necromantic. I must admit my Warhammer Fantasy lore isn't really up to snuff but isn't Undead & Necromantic kind of the same thing? Seems like an odd choice to release two similar races as new DLC but I could be completely wrong on this one so take what I say with a few dozen grains of salt.
Here's the full set of information straight from Blood Blowl 2's blog post:
"As we want to thank you all for your support since the very beginning helping us make Blood Bowl 2 a great success,
As long as you own Blood Bowl 2 before the launch of a race DLC, you’ll get that DLC and subsequent DLC for free, from the list of four planned DLCs.
The first new race to come (the Norse) should be available at the end of February. The three races remaining will release one after the other on a regular basis.
Thank you once again for your constant feedback and support on Blood Bowl 2,
See you on the pitch!"
As for whether Blood Bowl 2 is worth it, I'm not sure what to tell you. No matter where I've looked it seems to have mixed reviews with complaints and praise being spread across all game features and DLC practices. I am afraid I cannot give you a suggestion to go either way in this case so if you find yourself interested in Blood Bowl 2 I'd recommend you do your research before jumping in.
The first DLC is coming at the end of February so you have plenty of time to make up your mind or catch it on some sort of discount, during the quickly approaching Steam Christmas sale for example.