Would be nice, but there are other security measures you can also take to prevent being hacked. I've only had a forum account hacked once and that was because I sold an account and the account had the same password as my forum account - stupid me.
Just be safe with what you're doing and take the necessary precautions and there shouldn't be a problem.
Of course it's always nice to have, though.
As long as the two step process is a voluntary thing and not mandatory, I don't see the problem in implementing it. It couldn't really hurt anything.