There is one thing that Ed`s death has given us.
Roy now cannot die.
This face off between he and Pride has been built up since the moment you meet them. The tension has been rising all along, "Roy for Fuhrer, Roy for Fuhrer."
It was possible all along that Roy could die in the battle and leave everyone with a deep "WTF?!" feeling of unexpectedness ... BUT ...
Ed was just pwned by Envy. After having Envy plunge his arm through Ed`s chest with 2 seconds left in the second to last episode ... there is no WTF that can compare.
So I think we can be farely certain that Roy is going to survive this series.