http://groups.google.com/group/openscales-dev/browse_frm/thread/906ffcee5ac35f35/8c93158cd1d59403?lnk=gst&q=point+symbolizer#8c93158cd1d59403
The general idea is that you (1) create a style for your WFS Layer and
(2) add a rule, and then (3) add a "PointSymbolizer" to that as a
renderer for whatever marker you intend to have. The point symbolizer
is the key, that is what will create the appearance of your
"respective" markers based on your "data value".
For markers I assue you might want to use the WellKnownMarker class.
Which uses evaluation expressions so you will also need to look at the
expressions class for when you evaluate your feature data values.
I am using OS 1.2, but that's pretty much how I did it.
GL
-Mike