Note: I've updated this popover post - find it here!
They actually popped this time! I broke down and bought a real popover pan. (about $17, Chicago Metallic, purchased at Freehling Pot & Pan in Hyde Park). I also used a new recipe this time so that could have made the difference as well. I highly suggest investing in a popover pan if you plan to make popovers.
This recipe called for warm milk and room temperature eggs, as well as 1 hour of allowing the batter to rest after it is mixed. So keep these things in mind if you plan to use this recipe.
I will have to try my other recipe with my new popover pan sometime soon to compare.