If the story does resolve it resolves with a horrifying ending as the narrator, in her desperate fight to free herself from her depressing confinement "releases" what she perceives as her alter-ego from behind the evil-colored paper that confines her, the hideously patterned yellow wallpaper being symbolic of the patriarchal repression under which she has suffered. That she must descend into insanity in order to be free is what creates the horror.
I agree with the earlier posters that there is no neat (and certainly no happy) resolution to the conflict in this story. In some ways, both the narrator and her husband are defeated, although her defeat is by far the more tragic. One could argue that the narrative reaches a kind of "resolution" in the sense that the narrator can't reach much more of a state of degradation than she finally does reach at the end. In a sense, the story "resolves" itself on a note of shock, when not much more suspense is realistically possible unless the narrator were eventually to die.
I agree with the above post, but would add that perhaps the resolution is that the narrator is proved correct in her belief that the rest cure is sending her mad. Also, her husband has dramatically discovered that she is not being a 'silly goose' when she complains of the difficulties her isolation is causing.
Well, I don't know if they were resolved so much in a positive way. The way in which the narrator at the end of the story literally assumes the identity of the woman who has been trapped behind the bars of the yellow wallpaper by walking around the edge of the room, even stepping over her fainted husband to do this, indicates that the story ends with her descent into complete madness.