Psychonauts 2 was announced at Game Awards 2015. Double Fine has launched an crowdfunding campaign on their own site fig.co (aka another Kickstarter, but only for games). You can help here. While writing this post, there’re 7640 backers and $1,013,216 of $3,300,000 (30% funded).
Psychonauts 2 gonna use UE4 (Unreal Engine 4) and will be released on Steam, DRM-free, gog,com (on Windows, Mac & Linux of course), PS4 and XONE.
Any informations are on game campaign page and here.