Hi Peter,
What kind of overlays are you talking about? Vector
overlays or
Mapnik-Styles? In the latter case there is no need as we need a custom
style either. In the case of a Vector-Style I'm not sure if rendering
streets via Vector-Layer would work but in any case I'd give it a try.
I thought more of mapnik-styles...
Mmmh.. as you can import style-files into another, maybe I'll try to
separate osm.xml into landuse.xml, natural.xml, railway.xml, etc. So
if one wants his own street-rendering, one can simply include the
above xml..
Regards,
Thomas