As there is no official Magento 2 Roadmap (yet), I initiated an official inofficial Magento 2 Roadmap. The idea is to have a single point where you can find new stuff that is planned for Magento 2. This should make it easier for everyone of us dealing with Magento 2 to plan ahead.
You can find it at http://mage2roadmap.com
Contributions in form of Pull Requests are highly welcome to keep this list up to date. If you add a new item to the roadmap list, please provide a link to the source as well. Thanks!