I only get ttyUSB0, which is my GPS receiver. It does not show up as tty, which can be easily verified in the logs.
I also don't quite understand why switching from 8u2 to 16u2 would change the device ID such that it changes the name of the device. The Duemilanove would show up as USB because the FTDI drivers say their name is ttyUSBxxx, but the AVRs (as programmed by Arduino) use different drivers that say ACM. At least, that's how I understand it.
I wonder if I can load the R3 USB code into the R1, and maybe it will be recognized? As long as it's smaller than 8 kB of flash, it "should" work...