Go grab it from http://sourceforge.net/projects/cp210x-program/files/cp210x-program-1.0.tar.gz/download
This is a pure bugfix release. No new features.
So why does the version change from 0.x to 1.0? Well, precisely because of that. Given the very low rate of change and the steady number of downloads, it seems that the code is now mature.
The only big thing missing is programming GPIO on CP2103. Since I don't currently have that chip for testing, I simply decided this was out of scope for 1.0. I can If somebody can help with testing (or if I get a CP2103 to play with), it can go into 1.1. Otherwise, feel free to use a competing project (cp2103-config) for that.
Use PyUSB instead of importing C functions from libusb directly.