The current build is quickly approaching release status. This forum topic has traditionally held a list of items that were still outstanding TODO items -- nearly everything is now crossed out; the most significant item that didn't make it in for the deadline is the low-powered laptop graphics optimizations; which will now need to wait for a post-release patch.
Big items:
Diplomacy and Events (More info available in these posts.)
Various unimplemented technologies and racial special features
The ability to filter parts / systems appearing in the ship designer screen.
Improved UI layouts and cursors. (See also the UI FAQ.)
The ability to change the zoom level of the the galaxy map.
A reduced visual quality setting that should make it easier to play large maps on older/lower powered laptops.
There are also a number of things that we're really hoping to get finished in time for the release, but which aren't yet on the official "must have" list. These items include:
An interactable tech tree visualization in the research screen.
