The press release makes it official.  Portal Server 7 is shipping.  The press release implies it's available for download now, but the download pages are still serving up Portal 6.  Wait until next week, the PS7 bits should hit the site then.

The collaboration features are definitely the highlight.  The portlet features in Creator are also mentioned "...including drag and drop portlet development using the Sun Java Studio Creator".

Update: Portal Server 7 bits are now available for download.