I do not have it installed now, but if I remember well, on the beta I renamed all Eclipse zend debugger plugins. I think they were two or three. I have just added a ".no" at the end of the name changing their extensions.
I then restarted FB for PHP, and in the options I was finaly able to insert my XDebug parameters. I hope it still works like that with the release version.
The files to rename are:
I simply renamed them to:
After that, xdebug magically shows up in the installed debuggers list.