Talk about stupid.
1). The new interface is slower, (thumbnail images slowly fill in once you scroll down the page -- you can actually watch the images paint onto the screen 'cause it's so slow).
2). They made the fonts smaller on most of the nagivation -- that should help all the grandparents shopping for Christmas gifts.
3). They junked up the screen with "holiday" gift icons, reminders, etc.. enough to bug anyone who ISN'T Christmas shopping.
4). they have changed the search refinements in many categories -- so long time users now have to stumble around trying to get the site to produce the results they want.
5). Changing ANYTHING in the 60 days before Christmas --- that's a good way to alienate your established customer base.
With that said, if you are selling online, and want to confuse and alienate your customers, decrease sales during the busiest selling season of the year, and generally give your visitors the feeling that you could care less about their online experience -- follow eBay's lead.