Basically two issues holding things up:

1) The directory structure when you unzip the bundle has changed. The app server directory and the deploy directory are now both inside the main installation directory. This changes the path for starting the app server:

[install.dir]/tomcat-6.0.18/bin (or whatever app server you're bundled with)

as well as where portlet .war files are hot-deployed:

[install.dir]/deploy (rather than [user.dir]/liferay/deploy)

2) It appears that we have a problem with doubly compressed JavaScript (again? I thought we ran into this previously but couldn't find a JIRA). In order to get Component Showcase portlets running, I had to add the following context parameter.

<context-param>
<param-name>com.icesoft.faces.compressResources</param-name>
<param-value>false</param-value>
</context-param>

This means that we aren't compressing the resources we normally would. The reason this is necessary is that, as part of the hot deploy, Liferay now injects a bunch of filters into the deployed web.xml as well including:

...
<filter>
<filter-name>GZip Filter</filter-name>
<filter-class>com.liferay.portal.kernel.servlet.PortalClassLoaderFilter</filter-class>
<init-param>
<param-name>filter-class</param-name>
<param-value>com.liferay.portal.servlet.filters.gzip.GZipFilter</param-value>
</init-param>
</filter>
...
<filter-mapping>
<filter-name>GZip Filter</filter-name>
<url-pattern>*.js</url-pattern>
</filter-mapping>
...

There may be a way to turn these filters on/off selectively for the portlet, but it's probably easier at this point to simply turn off our compression. So bottom line is that it should possible to get ICEfaces portlets running with Liferay 5.2.1.

Someone logged an issue in the Liferay tracking system as well:

http://issues.liferay.com/browse/LPS-1998

The bottom line is that Liferay compression will remain enabled by default and that those that don't need it should turn it off.