1.integrating FB in Dolphin is not good. but it is vital for Dolphin's growth
so, the idea is integrate all social networks and present in a magically different way. that will work.
ppl can use dolphin as a social aggregator to post across many social networks. instead of logging into each and every websites.

2.to make this happen, there should be some reason to "like" D-based social aggregator
a) does it have IM to keep in touch with all my friends always?
b) does it have super see more cool cityville like social games?
c) can i create pages?applications? on my profile?
d) can i access D-network via my mobile browser?
e) can i interact with my friends/network in a fun/interesting way other than "poke" "like" "polls"

there are lots of logical questions to debate Dolphin with facebook
if Facebook is a huge dinosaur we can kill it someway...
its a highly intelligent swine flu...