Between the Bird's Nest and the Water Cube was an open park area, decorated with 2 rows of Christmas trees. There were a surprising number of people there, considering that nothing much was opened and it was sub-zero and totally freezing.
I liked the Water Cube enough to brave staying out a bit longer, and walked up close to take a few photos of it.
Apparently to be allowed to swim there, you need to pass a proficiency test first. It didn't look open to me, although there was a little gift shop in a separate building next to it where I sought refuge for a few minutes to thaw my frozen hands...
In all, I spent a full hour walking around to take photos of the Bird's Nest and Water Cube. Even though I was warmly wrapped up, the temperature and wind chill were so bad that my eyeballs were hurting!!! Next time I come back here will be in summer...