Hi Mantra,
I think this gives some complications.
First: People can comment without registing, this means they don't have an e-mail address.
Second: Not everybody wishes to let their e-mail address been seen by everybody so they would not like their address to be included with their comment.
Besides these problems I think it is possible, but I would give some more thought about the issues I just mentioned.
Cheers,
Vraxor