Don't worry about desoldering. R2 should not be there; look, for example, at the photo of the official Duemilanove at http://arduino.cc/en/Main/ArduinoBoardDuemilanove
. The resistor is a small 0805, just touch it with a soldering iron, and it will get loose.
If you insist you don't want to touch it, you can use the serial port without the onboard FT232, but then you will need to manually reset the board (push the button) at the exact time when avrdude starts looking for the bootloader. Pressing reset makes the board execute the bootloader, which looks for avrdude on the other side of the serial port. If there is no avrdude there, it transfers control to whatever sketch has been uploaded. You will have to experiment with the timing of manual reset. This is a workaround; desoldering R2 is much easier and is the correct way to make the board work.