Lately in November SQL Developer 3.0 EA is out integrating the "Map View" already.
Suggest to Download SQL Developer 3.0 !
An update has recently been made for the GEORAPTOR extension in a sourceforge project.
GEORAPTOR is a "viewing component" for the SQL Developer 2.1 to have a first impression of the spatial data used.
You may find more info in my older post here.
The name GEO-RAPTOR originates from the former "development" - name of SQL Developer, which was called: RAPTOR (;-)