My wife decided to stick with Guinness to avoid screwing up the recipe, leaving us to try the Cobblestone at a later date when it'll just be us eating the cupcakes. :)
Now I have two can's of Cobblestone and a few Guinness sitting in the fridge on St. Patrick's Day. Is there a better day to crack them open? I think not.
This afternoon we'll be having a Stout-Off.