Let me try to guess:
the batch letter printing on Dec. 14~17 (Tue-Friday),
the letter sending out on Dec 15~18(Wed-Sat. Post office working time).
the earlier letter received by the lawyer/employer/agent:
on Dec 17,18, 20~23 (Dec 24 is Christmas holiday) 26~29 (if mail to S.F).
so the ealiest person who will get phone call from the lawyer/agent would be Dec 18,20~23, kind of Christmas gift, although it is only a confirmation/information letter, it is still a hope someone are taking care of our cases. so be patient until Dec 18 to post letter question (this is only my personal guess)
then only after 45 days (is business day or just relugar days?), they will process the applications based on L.O date (priority date, the date SWA received your case). it will be Feb 1st 2005. so I guess during the whole January we will discuss the contents of 45 letter. only after Feb, we will hear some positive approval....
have a nice afternoon..