Allow access for all lightmaps to be im- or exported. This opens all possibilitys for external renderer to provide lightmap calculation.
Would work hand in hand with ticket 57 http://trac.cafu.de/ticket/57 -Need for 2 different uv channels (one for the usual material and one for the lightmap, which is auto calculated.
Possible feature: option to pack certain bsp parts (and meshes ?) into one big pack, auto unwrap it, export mesh and lightmap UV set into another application. Then load the lightmap back into editor, done.