added coming soon to parts of the docs, linked scoped_session

docs/conf.py

@@ -241,5 +241,6 @@ latex_documents = [
 
 intersphinx_mapping = {
     'http://docs.python.org/dev': None,
-    'http://werkzeug.pocoo.org/documentation/dev/': None
+    'http://werkzeug.pocoo.org/documentation/dev/': None,
+    'http://www.sqlalchemy.org/docs/': None
 }

docs/patterns.rst

@@ -226,7 +226,10 @@ Here the example `database.py` module for your application::
         Base.metadata.create_all(bind=engine)
 
 To define your models, just subclass the `Base` class that was created by
-the code above.
+the code above.  If you are wondering why we don't have to care about
+threads here (like we did in the SQLite3 example above with the
+:data:`~flask.g` object): that's because SQLAlchemy does that for us
+already with the :class:`~sqlalchemy.orm.scoped_session`.
 
 To use SQLAlchemy in a declarative way with your application, you just
 have to put the following code into your application module.  Flask will
@@ -276,6 +279,16 @@ Querying is simple as well:
 .. _declarative:
    http://www.sqlalchemy.org/docs/reference/ext/declarative.html
 
+Manual Object Relational Mapping
+--------------------------------
+
+*coming soon*
+
+SQL Abstraction Layer
+---------------------
+
+*coming soon*
+
 
 .. _template-inheritance: