I tried the same dates as OP and I'm not getting this awesome price.
Congrats to all who snagged it.
I think its still there, just not for those exact dates. I did a quick search and found Mar26 - Apr 2 for $814.56 (Canadian$). That translate to $652. Thats actually cheaper that what the OP quoted based on today's exchange rate.
Deal is best if flying thursdays, but tuesday flights are about $100 more.
Excellent deal, but thursday-thursday flights don't work for me in terms of maximizing vacation...