after checking the bug page for something else, I found

This is very simple assuming you have a monitor. If you don't, just try to type as follow :

first wait 5 minutes to let the rpi to boot properly.

you will be prompted for the username and password.

root [ENTER]
toor [ENTER]

then you want to install the ssh package :

apt-get install ssh -y [ENTER]
wait at least 5 minutes if you don't have a screen plugged

then :
update-rc.d ssh enable [ENTER]

wait 10 seconds, then :

reboot [ENTER]

you should be good for the glory and power.

I did not tried without a screen those command, but that's what i did first to get ssh working on my rpi.