Important Note: This item has been changed since it was first posted. The WSDL version was corrected, and the information about searching based on availability has been removed. The searching capability worked fine on our test servers but did not work as expected when we put it into production. We will fix this problem as soon as possible; watch this blog for updated information.
We have rolled out a new release of ECS today. The WSDL file is dated 2005-07-26 (a previous version of this posting listed it as 2005-07-27, which was incorrect).
New features in this release include access to additional product images (including color swatches), spelling correction in ItemSearch, inclusion of the Subject field in the data returned for books, inclusion of the MPN (Manufacturer's Part Number) for each item, better search results using so-called binned searches, similar products, new releases, and top sellers returned as part of the results of certain shopping cart operations, access to new releases and top sellers for each browse node, better support for the Classical Music search index, and documented support for the return of compressed (gzipped) XML responses, along with a number of important bug fixes.
For full information please consult the Release Notes and the Programmer's Guide. Please note that early versions of these documents contained references to the incorrect WSDL version and to the searching based on availability.