mcjeff@martian:~/cpython$ ./python -V
Python 3.4.0a0

When an SSLSocket is created via SSLContext.wrap_socket, it is passed a _context parameter directly.  SSLSocket.__init__ sets self.context at this point, but it does not set self.keyfile or self.certfile.

However, in SSLSocket.accept, both keyfile & certfile are passed when creating a new, wrapped SSLSocket, from socket.accept's newsock.

The result is an attribute error.
>>> import ssl
>>> c = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
>>> c.load_cert_chain('Lib/test/keycert.pem')        
>>> import socket
>>> s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
>>> s.bind(('127.0.0.1', 5050))
>>> s.listen(5)
>>> s.accept()  # nc localhost 5050 in another term.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/google/home/mcjeff/cpython/Lib/ssl.py", line 557, in accept
    keyfile=self.keyfile, certfile=self.certfile,
AttributeError: 'SSLSocket' object has no attribute 'keyfile'
>>> 

Attached one-liner addresses it by passing in the context rather than the keyfile & certfile.

>>> s.accept()
(<socket.socket object, fd=4, family=2, type=1, proto=0>, ('127.0.0.1', 37306))
>>>

I don't understand your code snippet: you don't seem to wrap the socket anywhere (paste error?).
As for the patch, it would be nice to add a corresponding test in Lib/test/test_ssl.py.

Ak! Yes, cut and paste error.

Python 3.4.0a0 (default:57a33af85407, Oct 27 2012, 21:26:30) 
[GCC 4.4.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl          
>>> c = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
>>> c.load_cert_chain('Lib/test/keycert.pem')        
>>> import socket
>>> s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
>>> s.bind(('127.0.0.1', 5050))
>>> s = c.wrap_socket(s)
>>> s.listen(5)
>>> s.accept()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/jeff/cpython/Lib/ssl.py", line 557, in accept
    keyfile=self.keyfile, certfile=self.certfile,
AttributeError: 'SSLSocket' object has no attribute 'keyfile'
>>> 

I'll add a corresponding test, sure thing.

Updated to pass in the parent context only actually, as it doesn't look like all of the attributes on SSLSocket will be set if a context was initially passed in.

New changeset f475332df9b5 by Antoine Pitrou in branch '3.2':
Issue #16357: fix calling accept() on a SSLSocket created through SSLContext.wrap_socket().
http://hg.python.org/cpython/rev/f475332df9b5

New changeset 9510a9641c80 by Antoine Pitrou in branch '3.3':
Issue #16357: fix calling accept() on a SSLSocket created through SSLContext.wrap_socket().
http://hg.python.org/cpython/rev/9510a9641c80

New changeset 5fc30f0277a5 by Antoine Pitrou in branch 'default':
Issue #16357: fix calling accept() on a SSLSocket created through SSLContext.wrap_socket().
http://hg.python.org/cpython/rev/5fc30f0277a5

I've reworked the patch a bit and committed it. Thank you for reporting this!