No, we're not getting another dog just yet, although my wife has been bugging me a lot. Judging from how Rosco acts around other dogs, I don't think he minds be an "only dog" anyway. I think other dogs make him nervous, especially when it comes to food and bones. Now we can even pet him while he eats, something that made his lips curl when we had Teddy around.
I have come up with a name for our future new dog, though, and it's one that my dad would probably endorse: Underfoot.