Node.ACS allows developers to build fully-featured mobile backends using Node.js on Appcelerator Cloud Services. Some key benefits include: - Using JavaScript for both client and server code through Node.js - Integrating Node.js web servers and networking components directly with ACS' data services - Hosting multiple versions of an app and routing users to different versions The presentation demonstrated sample code for a login API and group chat app using websockets. Upcoming features include background job workers, monitoring, integrations with other services, and more flexible free tiers.