I think you have lighting enabled (which is now also default for the test scene node) without a dynamic light defined. Lightmaps were previously not affected by dynamic lights (was simply not working for OpenGL), but it's now also implemented. Try to disable LIGHTING or define a dynamic light source.
If you're talking about the fact that the cube is black, then I had the same problem. You have to turn off the lighting on the cube since now the default for cubescenenode is to have lighting on.
No, only the cube has changed to default settings (it was previously a test node so it used fail-safe settings), all other nodes should have lighting enabled by default before. But lightmapped meshes were not affected by light.