The next Elementary OS system will be named Isis, after the Greek name of the Egyptian goddess of Nature. For now, there is only a small amout of information about the next Elementary OS version. No official release date has been announced, until now. A full list of improvements and changes brought to Isis can be seen on the official Launchpad announcement.
As you may know, Elementary OS Luna has been released recently, being based on Ubuntu 12.04 LTS Precise Pangolin.
If you are an Elementary OS user and enthusiast, a full list of tutorials and how to guides for Elementary OS can be found here.