I was just out in Whistler over Christmas break, I was there from the 27th to the 1st. They got dumped on on the 1st, and a lot of the mountain was closed on the 1st because of the conditions. But now that it has presumably stopped snowing, I'd definitely head up there now.
We rode mid mountain the first two days, and then went up to Spanky's ladder and Whistler bowl on the 31st after they had gotten a bit of snow. Riding was INSANE. I'm from the east coast, so I had never ridden anything like it before. Anyway, I'd say definitely go check it out before it gets crazy busy with the Olympics.
Also, Longhorn was an awesome place to go drink and and have a good time. Met a good group of girls from the west coast and spent several nights partying with them at Longhorns.