I am sure we will see one soon, altogether perhaps not as soon as former Deputy Prime Minister Lord Prescott might like (see here). Shadow Cabinet members will be -- to different degrees -- fighting to retain their positions. It is uncontroversial that Labour has not capitalised much at all from a flurry of increasingly bad news from the government. I expect various ideas will be sounded out at the party conference meeting now in Liverpool with a reshuffle announced sometime over the next 2-3 weeks.
UPDATE: I was correct! Reshuffle announced here.