This reminds me a little bit of the (in)famous Insignia NS-B2111 bookshelf speaker, which, for those who don't know, was offered by Best Buy's house brand Insignia up until a few years ago, I believe. It turns out they were actually sourced from the same place as another speaker design offered by a company called Radiient, though their incarnation was slightly different (it included a super tweeter and had a better crossover than the Insignia version). Here's a link to a blog post with pictures of the two:
And, of course, closer to home in the headphone world we have this:
Assuming the Monoprice/Klipsch issue is just another example of sourcing the same design, and dvw above makes a good point about the drivers (so an outright copy would be rather difficult to pull off), it doesn't seem to be that uncommon an occurrence. I've also heard stories of a company ordering a design manufactured, and said manufacturer then turning around and (obviously without permission) selling the design to others for rebadging, so perhaps it's something like that.
Edited by Argyris - 4/8/13 at 8:59am