Snuffy
I'm not sure I haven't cracked open a wired controller to see if it's just a matter of figuring out the connections or if it would require the software to be modified.
In wireless controllers like brian said your odds are to get a CG2 but I've been wrong in the past. If you buy a "Special edition" like silver, halo, etc. those have been CG2 for almost 2 1/2 years now. The only ones that have gone back-and-forth between cg2 and matrix1 and matrix2 have been the plain black controllers.