Edit, post-downvote: I am a relative "early adopter" of Bitcoin, having used and audited and spoken on it ( http://vimeo.com/27653912 ) for some time now.
I think we all knew that something like this was inevitable, but the sheer volume of idiocy and scale of nonsensical forks seems to be tending toward the rather silly end of the spectrum.
So, to that end: "Oh brother."
Moreover, when you talk about scarcity in the context of their economic value, it's not the absolute number that's important but rather the market share that Bitcoins have in the democratic, decentralized, I'm-willing-to-put-money-in-it ecosystem, and that ecosystem's size.
It's just a matter of time until more early adopters realize there can be any number of systems, WebCoins, StuffCoins, FreeCoins, and there's nothing special about Bitcoins that differentiate them from someone else running the same code with a different universe-id (and slightly different rules for scarcity control).
And once people realize that, I think they won't put their money in it any longer.
The value in a currency is who accepts it. Bitcoin is well-established and valued by many. That can't be said for any of these other schemes.
That's true right now and is what I said: currently Bitcoin has a rather good marketing power over the masses, and alternatives failed to appear yet.
However, once other systems start to emerge and people realize there's no value in such coins except their advertisement, there will be no moat to protect Bitcoin from its competitors.
If it will grow, people will choose the best suitable cryptocurrency for their use. This is ruled by infrastructure (exchanges, software, marketplaces).
I don't see how alternative blockchains would be bad for bitcoins or cryptocurrency in general. The more alternatives, the better. If someone invents technically better cryptocurrency than bitcoin, I will be glad to switch to it.
However, looking at all the current infrastructure around bitcoin (exchanges, mobile clients, libraries, marketplaces, web shops) I don't see why people would switch to these (only slightly) better cryptocurrencies currently. However, it's really easy to switch from a cryptocurrency to another (eg. use the same JSON API, anybody can set up an exchange easily), so we might see some rapid adoption when a better alternative emerges.
Isn't that a problem for anyone holding a significant quantity of the previous incumbent?
Give financial, material, or moral support to: "go up there and tell them—I'll back you up".
I think the military falls under material support.