We were there 10th - 14th for Avengers weekend. Tree was up, Christmas Parade was running, Jingle Cruise was running, Holiday World of Color, Fireworks and Small World were running. Christmas merchandise was all out. Seemed very Christmas-y to me.
They start putting stuff up right after Halloween. I was there the 5th and 6th and a lot of decorations were already up along with merchandise in the stores. Jingle Cruise and ISAW were still closed however since those take longer.
Just to add that although Christmas time in the parks is usually full swing on their beginning date (Nov 10th this year). the hotels don't usually get fully decorated until around the week before Thanksgiving.
I'm curious if anyone knows...are a lot of decorations already down by Jan. 8th? (Or last day of the holiday).
I went November 13-15, and while the parks were really well done, the hotels and DTD Disney were not. We were staying onsite and I was a little disappointed that the lobbies weren't done up. I have tossed around the idea of going Jan 8th to see PtN (because I have still haven't got a chance to see it!!! Grrrr) and I'm curious if most decorations will be down by then?
I think you will find the same type of thing, the Hotels and Downtown Disney will have most of their decorations removed, but not much removed from the parks until after Sunday night (1/8). Though they do have a need for a quick turnaround, since a major Holiday and Marathon weekend will be 4 days away.
They do leave up the "small world" area decorated until after "small world holiday" ends in late January.