Its a content management system that allows you to easily host and serve content on the IPFS filesystem, which is a decentralized datastore currently deployed and serving millions of documents. You can communicate with your peer network (friends) using blog-style posting techniques, share files (video/audio/html/etc.) and host them seamlessly on IPFS without requiring a centralized authority.

Pretty much anything I'd want to do on Facebook et al., I can do on Akasha - with the difference that I control the content. This is significant for content-creatives because it puts them back in the drivers seat for who and how their material is served.