Hi, I have few sites no google SERP results after 15 December, but my site keep increase indexing in Google. Please let me know, if you have any Ideas of Google.
I am having the same problem for one of my websites as well... it ranked very well accross 50s keyphrases but now the rankings are mostly vanished. Looks like a collateral damage on innocent sites for me...
Is the site ranking for its brand-name/domain without the TLD? If it is just keep cool and be patient. It will surely come back.
Maybe google is just doing a SERP update. Yesterday my site is on first page about 6 - 8 for a certain keywords. Now it goes back to 2nd page.