I'm not so sure that the "copy cat" eGos are really copy-cats in the sense most people are thinking. More likely they are made by the _same_ manufacturer, just being sold to many people besides the original customer who designed them.
When you sign on a manufacturer in China you usually try to get them to agree not to produce your product for other customers. But even then, if they have other resellers demanding the product it will be very hard for them to say no to their one original customers when there are dozens more dealers willing to take it. I'm not saying it's right, just that's how it's done.
This is actually what happened to Cisco if you are familiar with that debacle. A lot of journalists were calling them knock-offs/counterfeit, but in fact they were being produced in the same factory and identical to the legitimate products, only unlicensed. Perhaps being built on a clandestine overnight shift, for example. Contrary to popular belief it is extremely hard to make an indistinguishable clone of such a technically advanced product.
Electronic products usually contain software which gives the original designer a high degree of protection from such a thing, at least in the USA and Europe, through force of copyright. However for a simple piece of machined steel it is very hard to get any IP protection and if your manufacturer decides to screw you, well... you're screwed.
As I mentioned in another thread there is a concept of "trade dress" which is different from both copyright and patents, and most probably could be used to enjoin unauthorized channels from selling the eGo, at least in the US. Will be interesting to see how this plays out, but my guess is these designs will keep improving and we are unlikely to see major squabbles over particular iterations as they are superceded by better ones.