AAMOF, I just received 2 of the CP2102 adaptors yesterday, bought from a no-support/no-docos site on ebay, LOL. As noted, I tracked down the correct driver on my own, and installed. The loopback test worked fine.
However, does it work properly with my Arduino board? --> not hardly. Two problems:
1. the RXC and TXC pins on the adaptor are labeled backwards - depending upon your orientation.
They indicate the pins to connect to on the Arduino board, not the signal directions on the
adaptor.
2. the reset feature doesn't work. To upload a sketch, I had to hold down the Arduino Reset
switch, and release it shortly after the upload had begun.
So, 2 strikes.
The reset pin on the adaptor header is connected straight into the CP2102 chip, so

And yes, I have a 100nF cap in the Reset line on the Arduino board, plus a 10K pullup to 5V. I also tried running the Arduino chip at both 5V and 3.3V, plus tried the 2 extra pins on the adaptor header in case RST is mislabeled.
Also, when you look in the Control Panel Device Manager, there is no option available for changing anything on the CP2102 adaptor, such as "set RTS on close", as on regular FTDI cables.