If there is a demonstrated demand for such devices at 'rip-off' prices, that will encourage more development along these lines and we'll be seeing genuine commodity pricing that much sooner.
I think these current USB devices are just a curiosity at this price point. Sending the signal that people will buy anything and everything at hugely inflated prices will do much harm in the long run. There's absolutely no need to enrich ASICMINER and contribute to the centralisation of the network(*) at the current time any more than it's happening already. Come autumn when Avalon's chips built into DIY and small-time projects are hashing all over the world, then the situation is different. But at the moment... nah.
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(*) I realise the USB gadgets will of course be hashing all over the world, but the BTC spent on them will give ASICMINER an even bigger ability to centralise more. The actual hashing output of the devices will be minuscule in the grand scheme of things.
I've got nothing against ASICMINER becoming stupidly rich. They were the first to get ASIC hashing as best I can tell, and I'm happy if they enjoy the fruits of their labors. Them doing very well will just provide that much more incentive for competitors to get in and get a piece of the pie.
I'm surprised that they are selling these things or any hashing power at all to be honest. It undercuts their own strategy. I guess they are either seeing the end of their strategy or simply see distributing hashing power as a way to fuck their competition and increase the resiliency (and shape the trajectory) of the crypto-currency ecosystem. Whatever the case, I see it as a big positive and am happy to support it.
I expect that the current 1st generation ASIC are probably very inefficient internally. Just quick and dirty hacks to get something out the door. As the chip logic develops, I'm happy if some of the designers are looking to target the market for small distributed devices. That is just my wild guesses on things though since I have no first-hand experience here.