Miners have largely kept their options open regarding explicit plans to mine the Bitcoin Cash chain. Naturally, it makes sense for miners to watch market reaction on the exchanges before taking the risk of pointing much hash power at BCC. Given all of Jihan Wu's past rhetoric, though, I imagine Bitmain will allocate some portion of its hash power to BCC. This could potentially create a feedback loop which supports the BCC price and causes other miners to defect.

I certainly don't see BCC overtaking BTC, but I'm not as confident as most people are that it will be worthless and irrelevant. If nothing else, as the OP points out, it will be nice to see the potential flaws of big blocks and dynamic block size front and center.