A perfect example is my question I asked about Robb's wife. She's apparently a completely different character in the show vs. the books so I thought it was okay to ask.
I don't think the question by itself is going to do any harm, but it could lead to further discussions that do.
And if your question deals with differences between the book and show, we're not really qualified to answer it. You'd get a better discussion in the book thread.
I still don't quite get the "middle ground" thread. I like the idea and attempt to make everyone happy, but I don't see how it doesn't eventually turn into another book thread.