As a side note, deploying the original war I tried in a recent AS trunk fails with:

12:39:58,448 ERROR [[/infinispan-server-rest]] Exception starting filter Resteasy: java.lang.ClassCastException: org.jboss.resteasy.spi.ResteasyProviderFactory cannot be cast to org.jboss.resteasy.spi.ResteasyProviderFactory
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.init(ServletContainerDispatcher.java:55) [:]
at org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.init(FilterDispatcher.java:39) [:]
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:462) [:]
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3286) [:]
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3887) [:]

AS ships with a different version of RESTEasy library which would explain this issue (latest AS ships 2.0-beta-2 whereas the war includes 1.2.1.GA). However, AFAIR in the past WEB-INF/classes/lib was deployed under a different classloader and hence this shouldn't be a problem.