Originally Posted by grolby
Yes, it will. "X-Speed" on derailers is nothing more than marketing buzz. The derailer doesn't care how many speeds you have. Your shifters need to match your cassette, that's it.
In this case it should work, but it's not quite as simple as "that's it".
For index shifting the throw ratio needs to be compatible, an 8-speed D-A would not be, a Campy would not be.