Yea, that'll never happen. Sadly, Frank & Dana are 2 guys whose ego's are so large, that they'll never come to terms. People bring up Ortiz & Penn being brought back, but Frank is a different kind of beast. The kind of beast who wants way too much money and status, and Dana just doesn't see what's so great about him.
That said, I'd like to see Frank come back and have a few fun fights with Franklin or whoever, but I don't ever see it happening.