Actually there are 5 new decorations and a revised tigris.
The revised tigris now looks like the layout of the side menu with a raised bevel title bar.
blue-gradient. For an example see the css-demo portlet
gray-graidnet. For an example see the rss portlets.
gray-graidnet-noborder. See the Iframe portlet prototype on the default jetspeed page
pretty-single-portlet: Works great for single page "application style" portlets. See JPetstore and Struts Demo. Also the title and portlet controls are hidden.
tigris-clear: Identical to tigris save for the portlet content background is clear instead of gray.
columns.vm has also had all tables removed.