Thank you all! I posted the news from my phone at work as soon as I checked the online ECAS. Yes, a relief indeed!
I was worried that their decision was going to take ages, judging by the stories in here, and that I was going to have to appear in front of a Citizenship Judge with a very thick stack of pay stubs that link up with each other -- just to establish 1460 days of presence. I had saved those stubs over the last four years for precisely this purpose. I'm glad this won't be necessary.
As for the oath notice, I don't know if you all are aware but there's this link http://www.cic.gc.ca/citcer/search-recherche-eng.aspx from CIC that posts all oath ceremonies, and where you can search by your province. I've been using it, and it looks like up to now, my Hamilton office has been having a ceremony once a week. I hope that's the case going forward.
There was one guy in here with handle allawy86. He took the test with me at the same date, same office. Since he got approved at the interview, he got the oath letter literally ten days after. I don't know if that means I'm going to get an oath letter in ten days but I hope it won't be three months.