In the United States we are saddled with Schylling as a distributor for BRIO toys. I use the term "saddled" deliberately: we tend to get "new" releases anywhere from six months to a year after they have already been out in the European markets, assuming we even get them at all. Schylling picks and chooses which items it's going to bring in from BRIO's catalogs, and we are stuck with their choices and their timing. The good news is, there are options for you if you are interested in some relatively recent Wooden Railway products.
First, Schylling has released their catalog supplement for 2015 and it looks like the Fun Park theme will be available in the U.S. for the holidays. Also showing up will be the all new #33766 Railway World Deluxe Set, a huge starter set with a nice mix of some recent accessories. Based on Schylling's dealer pricing, expect the latter to run about $400.
If you want some of the Fall 2015 products, a few 3rd party sellers from Europe are listing items on Amazon's U.S. site, and selling at very reasonable prices with either free or very cheap shipping. This week, I noticed LeVida Toys listing most of the Horse Farm theme, including the large #33791 Horse Stable. A couple of other sellers have these items listed as well. Be sure to look around.