http://store.steampowered.com/app/22364/

get it in the first 2 weeks (? i think) and you get to keep it for free!

(downloading it, it doesn't requier you to pay and get reimbursed, it's directly free, a 480MB download (or a bit more if you include the 5-6 30MB downloads there were in the past month or so).

good news!
it seems all the abilities and such are there

bad news!
it seems they forgot to make the new maps selectable in the freeplay menu or in the campain menu...... yay!

or that's due to needing a reinstall of the game on steam (other people have had access to the game but many also have the problem I have). I did 2 file checks and the second one, after the OK all is fine, relaunched the download of the DLC ^^, haven't had the opportunity to test it again though.