They're showing off the next couple stretch goals as well as a new optional add-on survivor.
From the campaign:
We're just 5 days into this awesome Kickstarter campaign and we've already hit a $1 million dollars! Of course we don't want to leave you in suspense so here's the next two stretch goals!
At 1,050k We'll be unlocking the incredibly dead Storm of Crows for all Patient 0 and Infected level pledges!
We're also adding in another optional buy for you guys!