Yeah, i think it's just BU. Time that we see some really significant correlations between news from BU and BTC price declining, like we had them quite often in the past when Wu (or some other big pool) was posting in favor of BU and price immediately tanked. Let that happen several times and price below 700$ and BU-folks start to consider if it's actually the right path to choose.

And no the real shitstorm hasn't started yet, in case of a forking-mess better expect a combined price of below 500$.