The magic Mouse is a pretty straight forward accessory...so I doubt they'll be revising it anytime soon.
To be honest though, depending on what you want to do with it, there are better options...I do a lot of graphic design projects daily and found the magic mouse is a little clunky when it comes to precision...nothing even remotely close to my wacom tablets abilities (which should be obvious).
I really only ever use the magic mouse on my Mac Mini connected to my TV for browsing from my couch. Works surprisingly well on micro-fiber, lol!