Let me just say right from the start that I like to see Wigan do well. In fact, as a Bolton supporter, I like to see most smaller clubs from the northwest do well. Perhaps it is because I didn't grow up there, but I don't feel the animosity toward local rivals that some do.
That said, Roberto Martinez is a decent manager. I don't think he is going to lead Wigan to a top ten finish, how Paul Jewell did that once upon a time is still a mystery, but but I expect him to keep them up without too much trouble.
Wigan may still lose some players before August 31, but they seem to have put together a brilliant scouting network in South America, and seem to restock with a few gems every year or two. In the last few summers they have sold Wilson Palacios and Antonio Valencia, but Maynor Figueroa and Hugo Rodallega have stepped in without missing a beat. The latest candidate for this is defender Antolin Alcaraz, who was outstanding for Paraguay in the World Cup.
A couple injuries and some bad breaks could pull the Latics down into the relegation battle, but more likely they will have one or two good runs of form that will be just enough to safely ensconce them in the 13-16 range of the table.