rlange - 1:00 pm on May 9, 2011 (gmt 0)
"Not updated daily" is still pretty vague. I don't know if the following is a clue as to the actual interval, but...
A handful of my company's websites were hit by P2 (April 11). At some point between April 27 and April 29 two of those websites completely recovered, traffic-wise.
The two websites are related—near-duplicate content, but not a 1:1 ratio and in different languages; English and Spanish—and I've made no updates to either website since they were hit.
None of our other, larger impacted websites have seen any noticeable recovery. On one of them I've actually been experimenting with individual pages with no success.