The development system is the main source where issues and ideas are added. The status of things are updated on an ongoing basis. It's also possible to discuss stuff here, but if the main point of something is discussing or talking about it, use the forums instead :)
There are of course some other things being worked on not found here as well. Either stuff I simply haven't bothered to add, or forgotten about, or for e.g. security reasons choose not to include. It doesn't nearly contain every idea/etc either, but eventually it probably will :)
Updated June 17, 2015