Wilson is a red herring. There are still 4 episodes left and 13 is confirmed for the last 2 with the last episode being titled "Everyone Dies". I'm betting the Wilson cancer thing is just to make you think he'll be the one who dies in the end (or one of them if they're planning multiple) but I bet he survives through the finale while either curing himself because he's an expert as his own illness, or he gets better enough but still only has months to live after the season finale. My bet is still on House killing 13 in the finale (why else would she be back for the last 2 episodes?). As far as House offing himself, I don't know what to think about that yet. It just doesn't seem like something he'd do, but if he can't cope with killing 13 and he knows Wilson is either dead or dying, maybe they do a fade to black with him contemplating it and you don't know whether he actually "pulls the trigger" or not to end the finale