China is already clamping down on BTC. Wait till the US intelligence agencies find that it's being used by ISIS (or some other villain du jour) to fund/support domestic terrorism. When Coinbase and other exchanges are regulated out of existence and no US-based corporation can legally transact in BTC, the price of BTC against major currencies will collapse.
Ignoring the price of BTC, I would bet against Bitcoin purely on technical grounds. If the transaction fee history is correct [1], then it would suggest that the economic feasibility of Bitcoin as a payment service diminishes as it scales, and, with a peak mean transaction fee of nearly $9 USD last month, the blockchain cannot even support its own current popularity.