SB Nation's Pats Pulpit says the Laurence Maroney trade does not help the Patriots now, but as time goes on it should work out for New England:

Overall, I don't want to say that the Patriots are worse off without Laurence Maroney.  I would just say that the depth of the running backs, considering the group's age, is much thinner without Maroney.  Therefore, in the short term, this move certainly does not help the Patriots.

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When all is said and done, I really have mixed feeling about the Maroney deal.  I like the fact that the Patriots have cut their losses and guaranteed something in return for Maroney.  However, I don't like the depth the Patriots have at the running back position (considering the group's injury history).  I'll take a wait and see approach on this one, although there's no question the Patriots will have to address the running back position next offseason.