Sources have told me that certification flight testing on the 787 can start again as early as January 3rd though it still depends on the results of the Boeing flight tests (testing the software fix) and the FAA's final approval to resume the certification program.
ZA004 made a successful return to test flight yesterday by flying a 1 hour and 35 minutes test flight around the Seattle/ Puget Sound region.
Here's the current flight test statistics that I've been keeping:
On Dec. 20th there was a line move and the 31st 787 (ZA117/LN31 for ANA) entered final assembly in Boeing's 40-26 final assembly building. LN 27 (ZA178 for Japan Airlines) went to the paint hangar. I have a fully updated spreadsheet below of the current status of the 787s around Everett: