I'm fairly on the fence of this, but I have to ask: What standard are we using for BTC's enormous momentum? Its market price? The size of its goods and services economy? The amount of processing power committed?

It's really remarkable how Bitcoin has appreciated from literally nothing, but I can easily imagine a competitor stealing its thunder. A well-thought-out competitor could study Bitcoin's structure, early history, and problems, prepare a slick brand and tie-ins with major merchants, and destroy BTC's hegemony in a heartbeat.

Such a currency would lack most of BTC's ideological assets, of course, and many would still favor BTC for this reason. It wouldn't die out completely. But it won't necessarily dominate the online marketplace, let alone the global marketplace, without quite a lot of further good fortune.