Personally I think you guys need to take a chill pill.
Lots of companies make Tamagotchi-like virtual pets, so just because people on Ebay post them under the "Tamagotchi" name does it mean the product says so. JD, as far as I know, sure makes alot of fakes, but if you have a bone to pick, it should be with the sellers on Ebay posting them under the wrong name.
Also, as far as I know, if the V3 is roughly the same as a Keitai, then Japan should be near Version 5 or so. the Entama are Uratama should be V4, so as far as I can guess, there's got to be another one coming.
Truthfully, I'm enough to buy two of those fakes just to test them out. I've tried all Tamas out there that are True Bandai, except for the Devilgotch, because I cant find one, nor afford one, so to see how the JD verson stacks up to the real deal would be interesting.
In conclusion
For now, there's only V3 on the North American/European market, and the supposed V4/Entama/Uratama in Japan, so if it says anything over 5, it'll most likely be fake. Just make sure that it has the Bandai logo and reads "Tamagotchi". I've found some cunning sellers out there selling Tamas called "Tamagotos" and people buy them because they dont study the package well enough...