But seriously, sane projections have the Jays around 85 wins right now. That's not the playoffs. But those are mean projections, and if I'm remembering my SABR101 class correctly, it's not exactly unlikely for teams to fall anywhere within +/- 6 or 7 wins of their projections.
So the Jays right now, depending on reasonable randomness, should win between 79ish and 91ish games, with the most likely result being 85. So they have a chance to make the playoffs right now! Not a great chance, but a chance. Kind of like thehurl's chances of getting laid on any given Friday.
So adding one pitcher that represents a decent upgrade would of course increase their playoff odds. It's not like a team has to cross some magical line where the projection systems project 90+ wins, and all of those teams make the playoffs. That's not the correct way of thinking about things. The Blue Jays should definitely be adding wins right now, even if they can't find a way to add a huge amount.