Will Soft Serial work on the SPI pins?

I am laying out a bus between an AVR and another Micro. I would like to have the option to use either SPI or UART for communications between the micros. This means I would have to use the SPI pins on the Arduino with a SPI library. But if I choose to use UART instead of SPI can I still use those same SPI pins with the Soft Serial library? The documentation says Soft Serial should work on any digital pins, but I want to confirm this before I start soldering.

The documentation says Soft Serial should work on any digital pins

correct..

rwgast: But if I choose to use UART instead of SPI can I still use those same SPI pins with the Soft Serial library?

I'm not sure I follow you - if you're using the serial UART then you'd be using the hardware serial pins (0 and 1 for the standard Serial device). If you use SoftwareSerial then you can use any available digital pins, but they;re driven by software rather than by the UART.