It seems like only yesterday that we reported that Mike Dennelly was promoted to director of digital strategy at G2 USA. But now, numerous sources are telling us that Dennelly has resigned from his post after just four months. According to one spy familiar with the matter, Dennelly’s promotion was G2’s attempt to bring together several G2 agencies into “One G2″ and build its digital capabilities, but the exec was thwarted by in-fighting and lack of new business and digital work. From what we’ve been told, Dennelly, who had been with G2 for over five years, is headed to McGarryBowen to work on the digital side, though his exact position is yet unknown. We’re checking with both camps for more on the matter.