As far as I know Blender still has issues importing skeletal meshes via fbx and cannot export tangents or binormals. There is also the rotation issue when importing to Unity. This may be fixed with the new fbx scripts in 2.71.
What other artists said is true and this is my little game experience I'm getting in these days. I'm using Blender since 2.49 and I only can say that they improving it more than other 3d applications. I'm working to a game project, waiting to go on with vfx career, and Blender does its job perfectly for our indie project,…