Well, I wouldn't call them "copycats" (ultrasound is obviously a very different technology from accelerometers) - but in terms of the form factor and motion sensing in general, do you think anyone would be as open to the break-apart form factor if the Wiimote hadn't come out first and proved to be popular? This thread would be filled with a lot more "LOLs!" and "WTF are they thinking?" (though there are still plenty) like the first Wiimote thread was - as is, it's at least understandable why Sony thinks this controller would have appeal. It's not really an issue of who developed the technology or the idea first (I'm sure there were break-apart controller ideas before the Wiimote, as well as IR, motion-sensing, etc.), but Nintendo was first to take the risk with the mass market and the first to establish that it could be viable and popular. If Sony ever takes this to market (and that's not clear), it'll pretty much be in response to the general popularity of the Wiimote.
Sort of the same idea with the Avatars v. Mii's thing - it's not that Nintendo was the first to come up with the idea of using avatars in games, and Avatars are simply a copy...it's that introducing Avatars is clearly a response to the popularity of Miis, and not something that Microsoft just happened to independently decide to release now in a vacuum, etc.
