If you don't know who Catherine O'Hara is, I'm very surprised. Pretty much everyone I know has seen Home Alone, she played the mother, or one of her many other movies. And you would have a problem finding someone, English speaking of course, who is a fan of good comedy who isn't familiar with SCTV. But humour tends to be culturally related so it's understandable that a French Quebecer would not get it, just as most English Canadians or Americans wouldn't find Quebec humour very funny.
http://www.imdb.com/name/nm0001573/
As for the closing ceremonies, I thought the highlight was the way they handled the Olympic torch and was happy to see Catriona get her chance to light it. Avril looked very hot and it was a nice change from her usual 16 year old grunge girl look. It's about time she grows up a bit.

All in all I thought it was a nice send off to the Games. A shame that NBC cut their coverage at 10:30 to show that stupid new Seinfeld reality show. What a bad move that was.