it's far from completion. i think the first official beta is planned for the end of november. then the whole 2.5x series will be beta releases and some time after durian there will be a stable blender 2.6.

the graphicall.org test builds slowly start to get usable though. everything still is a bit rough but i really like the direction it is going and there are a lot of great projects in the works like bmesh and voxel sculpting. the new blender will be awesome!