As noted on the open beta download page,
The beta includes the IBM Thin Client for XML with WebSphere Application Server. The thin client allows access to the same Feature Pack API and runtime functionality (XPath 2.0, XSLT 2.0, XQuery 1.0) available in the WebSphere Application Server Feature Pack for XML. The thin client can be copied to multiple clients running Java SE 1.6 in support of a WebSphere Application Server V7.0 installation.
This means if you have client applications to WebSphere Application Servers you can copy the XML Feature Pack thin client file to these clients and get the same XML programming model support in your clients.
We also believe this thin client support will help "new to WebSphere" folks evaluate this technology. As such, we have added a download link to the jar file on the open beta website. Click on that link and then click on "Local install using Download Director or HTTP" and follow through to download "IBM Thin Client for XML with WebSphere Application Server
com.ibm.xml.thinclient_1.0.0.jar". I hope to show a demo of how fast you can get up and going with the thin client in the next day or so.