TCP

They may have been released at the same time, but as memory serves the Sixaxis was unveiled suspiciously after the Nintendo Wii, making it seem like a reaction to the Wiimote.

Whether it actually was in response to Nintendo's controller or not, we can not be certain.

Yeah, it did seem kinda suspicious at the time, though whose to say what was behind the decision. The ironic thing is that the Sony device that seems like the most blatant ripoff (Move) is actually the one that was in development well before any Wii announcement.

I wrote "whose to say". That's how I roll sometimes.