This actually received a lot of attention about three years ago, and probably at other times in history.
Frankly, I would say it probably isn't a good time, because it's clear there's no appetite for it politically in Canada or the U.S. So if you're asking me, am I going to devote a month to writing a paper about a common currency, I don't think there's any audience for it.
I did write a little paper, though, when it was very topical about three years ago. The theme of that paper was that for most of the arguments that are being used by the Bank of Canada and the Department of Finance against it, there are very good counter-arguments that don't get the play that they should. But you throw them up and say it really is a debatable issue from an economic point of view.