diff --git a/IPython/frontend/cocoa/cocoa_frontend.py b/IPython/frontend/cocoa/cocoa_frontend.py
index b366905..a713a2e 100644
--- a/IPython/frontend/cocoa/cocoa_frontend.py
+++ b/IPython/frontend/cocoa/cocoa_frontend.py
@@ -40,7 +40,7 @@ from pprint import saferepr
 
 import IPython
 from IPython.kernel.engineservice import ThreadedEngineService
-from IPython.frontend.frontendbase import FrontEndBase
+from IPython.frontend.frontendbase import AsynchronousFrontEndBase
 
 from twisted.internet.threads import blockingCallFromThread
 from twisted.python.failure import Failure
@@ -96,14 +96,14 @@ class AutoreleasePoolWrappedThreadedEngineService(ThreadedEngineService):
         return d
 
 
-class IPythonCocoaController(NSObject, FrontEndBase):
+class IPythonCocoaController(NSObject, AsynchronousFrontEndBase):
     userNS = objc.ivar() #mirror of engine.user_ns (key=>str(value))
     waitingForEngine = objc.ivar().bool()
     textView = objc.IBOutlet()
     
     def init(self):
         self = super(IPythonCocoaController, self).init()
-        FrontEndBase.__init__(self,
+        AsynchronousFrontEndBase.__init__(self,
                     engine=AutoreleasePoolWrappedThreadedEngineService())
         if(self != None):
             self._common_init()
diff --git a/IPython/frontend/frontendbase.py b/IPython/frontend/frontendbase.py
index 9a3b10e..87e7ac2 100644
--- a/IPython/frontend/frontendbase.py
+++ b/IPython/frontend/frontendbase.py
@@ -159,9 +159,6 @@ class FrontEndBase(object):
         - How do we handle completions?
     """
     
-    zi.implements(IFrontEnd)
-    zi.classProvides(IFrontEndFactory)
-    
     history_cursor = 0
     
     current_indent_level = 0
@@ -248,23 +245,7 @@ class FrontEndBase(object):
             Deferred result of self.interpreter.execute
         """
         
-        if(not self.is_complete(block)):
-            return Failure(Exception("Block is not compilable"))
-        
-        if(blockID == None):
-            blockID = uuid.uuid4() #random UUID
-        
-        d = self.engine.execute(block)
-        d.addCallback(self._add_history, block=block)
-        d.addCallbacks(self._add_block_id_for_result,
-                errback=self._add_block_id_for_failure,
-                callbackArgs=(blockID,),
-                errbackArgs=(blockID,))
-        d.addBoth(self.update_cell_prompt, blockID=blockID)
-        d.addCallbacks(self.render_result, 
-            errback=self.render_error)
-        
-        return d
+        pass
     
     
     def _add_block_id_for_result(self, result, blockID):
@@ -347,3 +328,44 @@ class FrontEndBase(object):
     
 
 
+class AsynchronousFrontEndBase(FrontEndBase):
+    """
+    Overrides FrontEndBase to wrap execute in a deferred result.
+    All callbacks are made as callbacks on the deferred result.
+    """
+    
+    zi.implements(IFrontEnd)
+    zi.classProvides(IFrontEndFactory)
+    
+    def execute(self, block, blockID=None):
+        """Execute the block and return the deferred result.
+        
+        Parameters:
+            block : {str, AST}
+            blockID : any
+                Caller may provide an ID to identify this block. 
+                result['blockID'] := blockID
+        
+        Result:
+            Deferred result of self.interpreter.execute
+        """
+        
+        if(not self.is_complete(block)):
+            return Failure(Exception("Block is not compilable"))
+        
+        if(blockID == None):
+            blockID = uuid.uuid4() #random UUID
+        
+        d = self.engine.execute(block)
+        d.addCallback(self._add_history, block=block)
+        d.addCallbacks(self._add_block_id_for_result,
+                errback=self._add_block_id_for_failure,
+                callbackArgs=(blockID,),
+                errbackArgs=(blockID,))
+        d.addBoth(self.update_cell_prompt, blockID=blockID)
+        d.addCallbacks(self.render_result, 
+            errback=self.render_error)
+        
+        return d
+    
+
diff --git a/IPython/frontend/tests/test_frontendbase.py b/IPython/frontend/tests/test_frontendbase.py
index ff68b6c..1498036 100644
--- a/IPython/frontend/tests/test_frontendbase.py
+++ b/IPython/frontend/tests/test_frontendbase.py
@@ -19,7 +19,7 @@ import unittest
 from IPython.frontend import frontendbase
 from IPython.kernel.engineservice import EngineService
 
-class FrontEndCallbackChecker(frontendbase.FrontEndBase):
+class FrontEndCallbackChecker(frontendbase.AsynchronousFrontEndBase):
     """FrontEndBase subclass for checking callbacks"""
     def __init__(self, engine=None, history=None):
         super(FrontEndCallbackChecker, self).__init__(engine=engine, 
@@ -44,7 +44,7 @@ class FrontEndCallbackChecker(frontendbase.FrontEndBase):
 
 
     
-class TestFrontendBase(unittest.TestCase):
+class TestAsynchronousFrontendBase(unittest.TestCase):
     def setUp(self):
         """Setup the EngineService and FrontEndBase"""
         
@@ -53,7 +53,7 @@ class TestFrontendBase(unittest.TestCase):
     
     def test_implements_IFrontEnd(self):
         assert(frontendbase.IFrontEnd.implementedBy(
-                                                frontendbase.FrontEndBase))
+                                    frontendbase.AsynchronousFrontEndBase))
     
     
     def test_is_complete_returns_False_for_incomplete_block(self):