Past 10g the current answer no longer works for renaming views. The only method that still works is dropping and recreating the view. The best way I can think of to do this would be:
SELECT TEXT FROM ALL_VIEWS WHERE owner='some_schema' and VIEW_NAME='some_view';
Add this in front of the SQL returned
Create or replace view some_schema.new_view_name as ...
Drop the old view
Drop view some_schema.some_view;