Technically the word is Sanskrit for "snake," and especially since most of Razer's mice are already named after scaly reptiles, we suppose it works. But given that the mouse is supposed to be designed for MMO gameplay (it has a twelve button thumb grid, supposedly to keep your hands off of spell buttons and on movement buttons where they belong), it's probably a happy coincidence that the name of the product is reminiscent of well-known villians in one very famous MMO. Good show, Razer.
They also have a new "mousing surface" (back when I was a kid, we just called them mousepads) called the Megasoma. Both are available right now, and they ain't cheap: $80 for the mouse, and $50 for the pad. But if you want to go high-end on a mouse, and the Naga strikes your fancy, there you go.