The exact same thing happened to me! PR4 was ranking very well and getting nice traffic from google, now im gone altogether. Just waiting to come back....
|ooks Like im experiencing what many many experienced in the last 2 yesterday my traffic 1/4 'd nows it a bout 1/10 , seems strange things are afoot at the ranch... only one thing for it add more pages, yay
I am repeating what other people are saying. I lost all my Google traffic end of december and it came back end of january with a PR4. One week later all the traffic was gone again and the traffic came back very slowly a few days ago. I lost indexed pages and the traffic is not back on the level before i lost all the traffic. Strange things going on with Google.
My site still has 18,000 pages indexed but still out of the top 100... I really hope the site recovers it's position in the SERPs soon...