Christmas SERPs changes

These days I noticed a lot of change in Google's search ranking pages and results SERPs.
I think this may be due to :
1- Holidays season, Google tries to make top reasults , top trusted ... these days have black hat SEO techniques at maximum ! it will be very embaressing if a site manage to get to top for a world like "Christmas gifts"... I think Google now gives top results to old trusted websites only !

2- The new Google Caffeine with new algorithms.

Yesterday I made a search then made it the same search 2 minutes later, the results were different !!
So, the sure thing there is something changed in Google algorithms at least for now.