Problems starting Nexus on Tomcat 6 on ubuntu

I pulled down the .war version (nexus-webapp-1.8.0.1.war) of the Nexus Open Source from the folks at Sonatype.

When I tried to deploy under Tomcat 6 on Ubuntu (10.10) the first thing you get is the following:

Dec 2, 2010 2:43:28 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/usr/share/nexus/WEB-INF/lib/servlet-api-2.5-6.1.12.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
log4j:WARN No appenders could be found for logger (org.sonatype.appcontext.AppContext).
log4j:WARN Please initialize the log4j system properly.
Dec 2, 2010 2:43:35 PM org.apache.catalina.core.StandardContext start
SEVERE: Error listenerStart
Dec 2, 2010 2:43:35 PM org.apache.catalina.core.StandardContext start
SEVERE: Context [/nexus] startup failed due to previous errors
Dec 2, 2010 2:43:35 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/nexus] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@591686f7]) and a value of type [org.codehaus.plexus.classworlds.realm.ClassRealm] (value [ClassRealm[plexus.core, parent: null]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Dec 2, 2010 2:43:35 PM org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
SEVERE: The web application [/nexus] created a ThreadLocal with key of type [null] (value [com.google.inject.internal.InjectorImpl$1@55f6efd2]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@46faf015]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.